MYTHIC ICONS - A new icon tier, Mythic, adds five characters: Yukine, Hiyori, Hinata, Kaguya and Hokuto. Each can be exchanged for 30 coins in the shop. Tap one to see it move and hear its voice. SHIMOYO SKIN AND KIWAMI PASS VOL. 3 - Added a new skin, Shimoyo, available for 100 coins in the shop. - The Kiwami Pass from November 1 is Vol. 3, "Shimoyo no Seijaku" (Stillness of a Frosty Night). It includes four profile frames, two titles and two icons. REWRITTEN STEP-BY-STEP SOLUTIONS - The step-by-step solutions in Units have been rewritten for most topics in Mathematics I/A, Mathematics II/B/C and Mathematics III. Each step of the working, and the reason for choosing each approach, can now be followed line by line. Solutions remain in Japanese. REWRITTEN COMMON TEST BOOKLET SOLUTIONS - The answers and explanations in the topic booklets and mock exams have been rewritten in more detail, including intermediate steps and reasoning. They remain in Japanese. - Points in the topic booklets and mock exams are now assigned to each group of answers. CORRECTIONS - Fixed errors found in some solutions and problem statements. CLEARER MATH LAYOUT - Long expressions no longer break in the middle of a term, or right after an opening or right before a closing parenthesis, when they wrap at the edge of the screen. - Vector arrows now span the whole label, and the labels on polar graphs no longer overlap each other. - Variation tables in the step-by-step solutions are now drawn as ruled tables, in the same typeface as the Common Test booklets. Thank you for using Sugoku. Send your thoughts any time from the suggestion box in the app.

59 COMMON TEST TOPIC BOOKLETS - Added 28 topic booklets for Mathematics I/A and Mathematics II/B/C, bringing the total to 59. Each includes a problem booklet and an answer-and-explanation booklet. - The newly added topic booklets are included in the Common Test Prep Plan. Existing free booklets remain available without a subscription. FIVE MOCK EXAMS FOR EACH SUBJECT GROUP - Mathematics I/A and Mathematics II/B/C now each have five full mock exams, ten in total. Each exam has its own problem booklet and answer-and-explanation booklet, separate from the topic booklets. - The first mock exam in each subject group is free. You can open its problems and answers and write directly on the booklet without a subscription. - Exams 2 through 5 are included in the Common Test Prep Plan. Open Mock Exams in Common Test Prep, then choose a subject group and an exam. REDRAWN FIGURES AND REBUILT PDFs - Figures in the topic booklets and mock exams have been redrawn. - The problem PDFs and answer-and-explanation PDFs have been rebuilt with the updated figures. Thank you for using Sugoku. Send your thoughts any time from the suggestion box in the app.

HANDWRITING ON BOOKLETS - Tap the pen button at the top right of a Common Test style problem booklet to write directly on it. Your writing is saved on your device for each page and is still there when you reopen the booklet. - Saving and sharing a PDF that includes your writing is now part of the Common Test Prep Plan. Turn on "Export PDF" in Settings after agreeing to the terms of use. Reading and writing on a booklet remain available for the free booklets. NEW RESULTS SCREEN AND ANIMATIONS - The results heading now reads RESULT, and your score and rating count up. - Promotions and rewards in Kyokuisen, and streak milestones, now come with bouncing motion and confetti. - The titles screen is split into two tabs so you can see your progress. New titles are earned through how you play, with an animation when you get one. COMMON TEST BOOKLETS REVIEWED - Typesetting of all 31 bundled booklets was reviewed so that fonts for formulas and symbols and page breaks are closer to the real exam. - Some booklets, including quadratic functions, exponential and logarithmic functions, sequences and calculus, have rewritten problems. Thank you for using Sugoku. Send your thoughts any time from the suggestion box in the app.

COMMON TEST PREP PLAN - Common Test style topic booklets now number 31. One per field, 14 in total, are free. - The other 17 are included in the Common Test Prep Plan, an auto-renewable subscription (¥480 per month or ¥3,800 per year in Japan). - Problem booklets and answer-and-explanation booklets were re-typeset to look closer to the real exam. KEY POINTS FOR EVERY TOPIC - Read a summary of formulas, when to use them, worked examples and common mistakes for each topic across Math I, A, II, B, III and C (free). - Open it from the book button on the topic list. In topic practice and review, tap "Formulas" above the keypad to check it mid-problem. MORE ENGLISH - When your device language is not Japanese, problem statements, answer fields and choices are now shown in English. FEEDBACK AND FIXES - Added easier problems on the maximum and minimum of a quadratic function on a closed interval. - If the app closes during a Kyokuisen match, you can resume on the same day: the problem on screen counts as incorrect and the match continues from the next problem. - Fixed overlapping elements in landscape on iPhone. - Reviewed the ratios and number combinations in some problems. Thank you for using Sugoku. Send your thoughts any time from the suggestion box in the app.

KIWAMI PASS VOL. 2 "KINSHU TO KITSUNEBI" STARTS OCTOBER 1 - New rewards themed on autumn leaves and foxfire: 4 profile frames (Chirimomiji, Kitsunebi, Tatsutagawa and Kinshu), 2 titles and 2 icons (Kitsunemen and Momiji). MOMIJI SKIN ADDED - A fifth skin with maple leaves drifting across an evening sky and distant mountains, lit by foxfire. Each scene has its own music. Available for 100 coins. PROBLEMS REVIEWED ACROSS 23 FIELDS OF MATH I, A, II, B, III AND C - Added new problem types. Examples include Math III limits where the method depends on the value of the ratio r, and Math A power-of-a-point problems with two chords that meet inside a circle. - More combinations of numbers and figures, so the same problem comes up less often. - Formulas in step-by-step explanations now follow textbook notation. - Fixed incorrect answers and explanations in some problems. REBUILT COMMON TEST PREP SCREENS - New material list and practice screen. The problem booklet is shown large, with the answer sheet in a drawer at the bottom on iPhone and in a panel on the right on iPad. - Enter one digit per cell with the on-screen keys; the next cell is selected automatically. On iPhone you answer one question at a time. On iPad all questions are listed, and you can collapse each one as you finish it. - After grading, see your score, a per-question breakdown and your previous score. Tap "Read explanations" to switch to the answer booklet. - The material list and practice screen now each have their own music. Thank you for using Sugoku. Send your thoughts any time from the suggestion box in the app.

FREE PRACTICE: EXPONENTIAL AND LOGARITHMIC FUNCTIONS - View, save, and share PDFs of the problem booklet and answer explanations. - Enter answers while following the booklet and receive a score out of 15. Thank you for using Sugoku. Send your thoughts any time from the suggestion box in the app.

IMPROVED ANSWER CHECKING - Equivalent recurrence formulas are now accepted when their two terms are written in the opposite order. - Reviewed other answers where factors or multiple real roots may be entered in any order. REVIEWED ANSWER FIELDS ACROSS ALL TOPICS - Fixed problems where valid answers, including some negative fractions, could not be entered. - Improved answer layouts and validation for fractions, radicals and line equations. BETTER INPUT - Improved voice input, external-keyboard controls, and delete/clear behavior in fraction fields. - Saved bookmark problems are migrated to the updated answer format. MUSIC FOR THE TSUKIMI SKIN - Added dedicated music for the title, practice, review, results and ranking scenes. Thank you for using Sugoku. Send your thoughts any time from the suggestion box in the app.

MONTHLY SEASONS IN KYOKUISEN - Seasons now change every month. Your rating drops by 500 at the start of a season and never falls below 1000. The season opening screen shows how your rating changed. - You can change your Kyokuisen division (school year and course) once per season. Your rating restarts at 1000 when you do. KIWAMI PASS ADDED - Earn pass points by solving problems and claim rewards across 30 tiers: 4 profile frames, 2 icons, 2 titles and coins. Three daily missions are available. Free for everyone. TSUKIMI SKIN ADDED - A fourth skin with a full moon and silver grass at night. Available for 100 coins. FRIEND REQUESTS NOW WORK CORRECTLY - Fixed an issue where accepting a friend request had no effect. Accepting, declining and removing all work now, and you can send a new request after declining one. REBUILT PRACTICE SCREEN ON IPAD - The scratch sheet now fills the lower half of the screen, and the keypad floats above it as a translucent panel. Move it anywhere, or collapse it to write freely. It fades automatically while you write. - Adjusted the problem text to a more comfortable size. LESS HEAT ON YOUR DEVICE - Reduced background motion during practice and reworked how the scratch sheet is drawn, so long study sessions stay lighter. OTHER IMPROVEMENTS - Fixed Premium season coins not being granted in some cases. - The leaderboard now lists only players whose records were updated this season. Thank you for using Sugoku. Send your thoughts any time from the suggestion box in the app.

MAKE YOUR PROFILE YOUR OWN - Added 40 rare anime-style icons and animated profile frames. The new shop lists icons, frames and skins available for coins. COMPETE WITH FRIENDS - Add friends by code, manage requests, and switch the leaderboard between nationwide and friends-only rankings. FASTER ACCESS TO KYOKUISEN - Start a match or open the ranking directly below the Kyokuisen button. Completing a match earns a coin, and Premium grants 20 coins each season. MATH I AND A FIXES - Reviewed quadratic functions, trigonometry, geometry, data analysis, permutations and more. Fixed ambiguous conditions, unreduced answers, mismatched diagrams, rounding issues and difficulty regressions. LIGHTER BACKGROUND ANIMATION - Reworked the title animation to keep its movement while reducing rendering load, and refreshed the cyber background formulas. Thank you for using Sugoku. Send your thoughts any time from the suggestion box in the app.

CHOOSE THE TYPE OF PROBLEM YOU PRACTICE - In topic practice, after picking a topic and difficulty you can now pick a problem type — for example, only internal division points, or only external ones. Available across Math I, A, II, B, III and C in over 250 places (the picker appears only where types exist; the usual random mix is still the default). STEP-BY-STEP EXPLANATIONS FOR ALL OF MATH C - Vectors, the complex plane, and curves — every Math C topic now has a full step-by-step explanation after you check your answer. Explanations are now complete for every topic in every subject. BETTER LAYOUT ON iPAD - Fixed an issue where the keypad or the answer button could be pushed off screen when a problem statement was long. Long problems now scroll. EXPLANATIONS NOW SHOW EVERY STEP OF THE WORKING - Step-by-step explanations in every subject have been reviewed so the maths no longer jumps from the substituted formula straight to the answer. Number-line diagrams now match the way textbooks draw them. MORE VARIETY IN MATH B - Hypothesis testing, recurrences, series and more — 17 topics now ask for genuinely different work at each difficulty, and repeat themselves less. Thank you for using Sugoku. Send your thoughts any time from the suggestion box in the app.

EXPLANATIONS NOW SHOW EVERY STEP OF THE WORKING - Step-by-step explanations in every subject have been reviewed so the maths no longer jumps from the substituted formula straight to the answer. The line where the numbers go in and the line where they are worked out are shown separately — the same order you would write on paper. - Number-line diagrams now match the way textbooks draw them. MORE VARIETY IN MATH B - Hypothesis testing, recurrences, series and more — 17 topics now ask for genuinely different work at each difficulty, and repeat themselves less. - Also fixed small display issues in explanations, such as the same value appearing twice, or a minus sign left in a fraction's denominator. Thank you for using Sugoku. Send your thoughts any time from the suggestion box in the app.

YOUR RATING NOW COUNTS EVEN IF YOU STOP PARTWAY - Until now, a Kyokui match only reached the leaderboard if you finished all 10 questions. Your rating is now updated after every single question, so if you have to stop early, the progress you made still counts. - Questions answered offline, or when the app was closed unexpectedly, are sent the next time you are online. A SMOOTHER STEP UP IN DIFFICULTY - New questions have been added to the tangent-chord angle, cyclic quadrilaterals and Σ summation. Where "normal" and "hard" used to ask for the same work, "hard" now asks for one more step of thinking. - The new questions come with step-by-step explanations too. Thank you for using Sugoku. Send your thoughts any time from the suggestion box in the app.

STEP-BY-STEP EXPLANATIONS FOR MATH III - All 43 Math III topics now show you how to get to the answer, one step at a time. How to break down an ∞−∞ limit, what to substitute in an integral. The places where you are most likely to get stuck are the ones explained most carefully. - Every topic in Math I, A, II, B and III now has an explanation. When a topic trips you up, you can check the method right there and keep going. EASIER TO READ - Exponents, roots, fractions, Σ and ∫ have been reviewed across every topic so they look the way they do in your textbook. - Prime factorisation answers are now entered as 2³, with the exponent raised. - VoiceOver reads these expressions correctly too. Thank you for using Sugoku. Send your thoughts any time from the suggestion box in the app.

DETAILED EXPLANATIONS - Step-by-step explanations are now available for every topic in Math I, A, II and B. See which formula to use, why, and where students usually slip. - Explanations use textbook notation too: horizontal-bar fractions, square roots with the bar, and raised exponents. Diagrams are shown where they help. MORE CONTENT - Added "Sums and general terms" to Math B (finding aₙ from the sum Sₙ). - Added "Continuous random variables" to Math B (probability density functions, where probability is an area). - Added geometric sums (Σarⁿ⁻¹) to the sigma topic, and the denominator of the answer is now yours to work out. - The app now covers 237 topics. MOVING TO A NEW DEVICE - Added device transfer. Issue a transfer code on your old device and enter it on the new one to carry over your player name, rating and leaderboard record. The code is valid for 10 minutes and can be used once. FIXES - Fixed a blank, unresponsive screen that could appear on problems that have both a diagram and a fraction in the answer field. - Improved variety so that a topic no longer repeats near-identical problems.

MORE CONTENT - Greatly expanded Math III: functions and limits, differentiation and integration (inverse and composite functions, rational and irrational functions, limits of sequences, rationalizing ∞−∞ forms, the floor function, and cases where no limit exists). - Added five topics on statistical inference and five on sequences. - The app now covers 235 topics. EASIER TO START - A short tutorial now explains the Kyokuisen rules (one attempt a day, rating, leaderboards by school year) the first time you open it. FIXES - Fixed a problem in "applications of recurrence relations" where a correct answer was not accepted. - Fixed broken formula layout in some problems.

【不具合修正】 ・特定のレート帯で正解してもレートがほとんど上がらない不具合を修正しました。 【その他の改善】 ・極位戦のレート計算をより公平でなめらかなものに調整しました。

【新機能】 ・「よくある間違い」と弱点単元への導線を追加しました。つまずきやすいポイントをその場で確認できます。 ・お知らせ機能を追加しました。アプリを更新しなくても最新のお知らせが届きます。 【問題の改善】 ・場合の数・確率の問題を大幅に多様化しました（順列・円順列・条件付き確率・独立試行・反復試行・期待値）。似た題材ばかり出る偏りを解消しています。 ・場合の数の答えを4桁までに揃え、教科書の水準に合わせました。 ・正弦定理で答えが自明になる出題を取り除きました。 【iPad・横画面の改善】 ・iPad の横画面で「答え合わせ」ボタンが画面外に隠れることがある不具合を修正しました。 ・横画面のリザルト画面を2カラムに再設計し、数式の表示崩れを解消しました。 【不具合修正】 ・音声入力で認識が途中で止まることがある問題を修正しました。 ・海スキンで効果音が鳴らない問題を修正しました。

・プロフィール機能を追加しました。アイコン（数学記号・キャラクター）と 二つ名を設定でき、ランキングにも表示されます。 ・解答を声で入力できるようになりました（音声はお使いの端末内だけで 処理され、外部へ送信されません）。 ・リザルト画面を刷新しました。極位戦はレートの変化とランク昇格が ひと目で分かるようになり、単元別演習はメダルまでの進み具合と 今回の10問の振り返りを確認できます。 ・銅・銀・金メダルのデザインを一新しました。 ・数学IIIに新しい問題（三角置換の定積分・極値から定数を求める問題）を 追加しました。 ・データの分析の難易度バランスを見直しました。

・数学IIIの微分法・積分法を大幅に拡充しました（新しい問題タイプ・基本公式・方程式や不等式への応用など）。 ・関数のグラフ表示を強化。三角・指数・対数・分数・無理・合成関数のグラフや、面積・回転体・接線・極値の図を追加しました。 ・「データの分析」に相関係数・仮説検定・分割表などを追加しました。 ・ランキングのレート増減バランスを調整しました。 ・細かな表記と操作性を改善しました。

数極 v1.1.0 の新機能・改善 ・iPad 版レイアウトを最適化：問題を大きく表示、テンキーは上下に移動でき、手書き用の下書きスペースも追加しました ・着せ替えスキンを追加（桜・海）。選んだスキンに合わせてアプリアイコンも切り替わります ・プレミアム（買い切り・¥300）を追加：ブックマーク500件／極位戦を1日3回／広告の非表示／解答タイマー・時間分析 ・お知らせに「開発者への意見箱」を追加。ご要望・不具合を直接お送りいただけます ・機種変更に対応：端末IDでランキング（レート・順位）を引き継げます ・新バージョンの更新案内をタイトル画面に表示するようにしました ・表示・操作まわりの細かな改善 いつもご利用ありがとうございます。ご意見・ご要望はアプリ内の意見箱からお気軽にお寄せください。