High school: credits, moving up a year, and the 文系/理系 choice made in year 1

Japanese high school (高等学校, kōtō gakkō) counts credits (単位, tan'i). One credit is one 50-minute lesson a week for a school year:

１単位時間を 50 分とし，35 単位時間の授業を１単位として計算することを標準とする。

A full-time school's standard week is 30 lessons. To graduate, a student needs at least 74 credits, the national floor; each school sets its own number at or above it. At the two Tokyo schools below, year 1 is mostly shared subjects, and at one of them the student picks a stream for year 2 during year 1.

Taking a subject and earning its credit

There are two steps. 履修 (rishū) is taking the subject; 修得 (shūtoku) is earning its credit. The course of study says the school must award the credit when the result meets the subject's goals, and it does so year by year.

One Tokyo school, 都立北園高校, spells out its rules for new students:

• Taking: attend more than two-thirds of the year's lessons (年間授業時数（３５週×単位数）の３分の２を超える時数を出席する). Missing a third or more means the subject is not taken (未履修).
• Earning: 学年末の５段階評定が２以上の場合は、単位を修得したものと認める。 A year-end 1 means no credit.

Under that rule a 2-credit subject (70 lessons a year) is lost at 24 absences, and a 1-credit subject (35 lessons) at 12.

The subjects everyone takes

Group	Compulsory subject (standard credits)
Japanese	現代の国語 (2), 言語文化 (2)
Geography and history	地理総合 (2), 歴史総合 (2)
Civics	公共 (2)
Maths	数学Ⅰ (3)
Science	科学と人間生活 plus one 基礎 subject, or three of 物理基礎, 化学基礎, 生物基礎, 地学基礎 (2 each)
Health and PE	体育 (7–8), 保健 (2)
Arts	one of 音楽Ⅰ, 美術Ⅰ, 工芸Ⅰ, 書道Ⅰ (2)
English	英語コミュニケーションⅠ (3)
Home economics	家庭基礎 (2) or 家庭総合 (4)
Information	情報Ⅰ (2)
Inquiry	総合的な探究の時間 (3–6)

Everything else (数学Ⅱ, 物理, 日本史探究 and so on) is chosen, and that is where the streams come in.

文系 and 理系: a school's stream, not a national rule

The course of study lets a school set streams (類型, ruikei) and requires free choices alongside them. Schools and families call them 文系 (bunkei, humanities) and 理系 (rikei, sciences). When the split happens is the school's decision. Two Tokyo metropolitan schools show the range:

	都立深川高校	都立日野台高校
Year 1	Shared base subjects	Shared, all subjects except arts
Year 2	Split: 文系 take 古典探究 and a history choice; 理系 take 古典基礎 and 化学; everyone takes 数学B	No split: ２年生までは文系・理系の枠を設けず
Year 3	Wide choices by stream	Choices by career goal

深川's page: ２年生から文系・理系などの進路希望に応じて科目選択を行い、３年生で大学受験に向けて重点的に学習を進めていきます。 At a school like 深川, the choice is made during year 1.

Moving up a year, and repeating one (原級留置)

High school can hold a student back: 原級留置 (genkyū ryūchi). The course of study asks schools to decide promotion flexibly, since they also count credits. Each school writes its own rule. 北園's says a student repeats the year if any one of these applies:

• any subject not taken at year end, electives included;
• two or more uncredited subjects at the end of year 1, or three or more in total at the end of year 2;
• at the end of year 2, 80 credits by the end of year 3 is no longer possible;

• 出席すべき日数の３分の１を超える日数を欠席した時。

北園 graduates students at 80 credits, above the national 74.

Credits from a year abroad

A principal may approve study at a foreign high school and count up to 36 credits from it (学校教育法施行規則 article 93), and may promote or graduate the student mid-year. The course of study also lets study abroad stand in for compulsory subjects when the result is equivalent. Ask before the student leaves, not after.

What goes wrong

• Absences pile up in one subject. The two-thirds line is per subject. If one class always falls on the same weekday, a run of missed Mondays can cost that subject alone.
• A single 1. At 北園, one year-end 1 means no credit, and two in year 1 means repeating the year.
• The stream closes doors. Streams are built around entrance-exam subjects: 深川's 理系 makes 化学 compulsory in year 2 so students can sit two sciences (理科2科目の受験に対応できます). A stream that drops a subject drops the exams that need it. Check first: university entry basics.
• Credit-based schools work differently. A school may run without year grades (単位制, 施行規則 article 103), so there is no year-by-year promotion step; see Tokyo public high-school types.

What to do now

1. Get your school's curriculum table (教育課程表) and its promotion rules (進級規定). At 北園 they are printed in the student handbook (生徒手帳).
2. In year 1, ask the homeroom teacher when the year-2 stream form is due and what each stream drops.
3. Keep a count of absences per subject from April, not just days.
4. If a 1 or a 未履修 warning arrives, ask the same week what make-up work or supplementary lessons the school offers.
5. Planning a year abroad? Get the principal's approval and the credit plan in writing before leaving.