What Is a “Koma”?
In Japanese schools and universities, the word koma (コマ) is commonly used to count lessons. Originally written as 齣, the word referred to a scene or section in a play. Over time, it came to mean a “frame” in film or a “panel” in comics. In the education world, it refers to a single unit or “block” of class time.
Example:
今日は三コマ授業があります。
Kyō wa san koma jugyō ga arimasu.
(I have three classes today.)
先生の持ちコマ数は週十八コマです。
Sensei no mochi koma sū wa shū jūhachi koma desu.
(This teacher is in charge of 18 lessons per week.)
二限は空きコマなので職員室で準備します。
Ni-gen wa aki koma nanode shokuinshitsu de junbi shimasu.
(I have no class in second period,, so I’ll prepare in the staffroom.)
The actual length of one koma depends on the school. In elementary school it’s usually 45 minutes, in junior high and high school 50 minutes, and in universities 90 to 105 minutes. In other words, “koma” doesn’t indicate an exact time by itself—it simply means “one class unit.”
Time Rules in Japanese Schools
Jigen (時限) / Gen (限) / Genme (限目)
These words show the order of lessons. In English we might say “first period” or “second period.” In Japanese, you’ll hear:
- 1-jikanme (一時間目) = first period
- 2-jikanme (二時間目) = second period
- 1-gen (一限) or 1-genme (一限目) = also “first period” (shorter and commonly used in junior and senior high schools)
Students and teachers will naturally say things like,
体育は三時間目にあります。
Taiiku wa san-jikanme ni arimasu.
(We have P.E. in third period.)
試験は一限目に始まります。
Shiken wa ichi-genme ni hajimarimasu.
(The exam starts in first period.)
Useful Related Terms
- Mochi-koma (持ちコマ): the number of koma (classes) a teacher is responsible for in a week.
- Aki-koma (空きコマ): a free koma with no class scheduled. Teachers often use it for grading or preparation.
- Jishu (自習): “self-study.” When a teacher is absent, students study independently in the classroom
Everyday Life in Japanese Schools
Homeroom (HR) / Short Homeroom (SHR)
Homeroom is held before and after the day’s lessons. Teachers use it to check attendance, give announcements, or hold brief discussions. In elementary schools, it’s often called 朝の会 asa no kai (morning meeting) and 帰りの会 kaeri no kai (afternoon meeting). It sets the tone for the day and provides closure at the end.
Cleaning Time
One unique feature of Japanese schools is daily cleaning. Students spend 10–15 minutes sweeping classrooms, wiping desks, and taking care of hallways or special rooms. It’s not just about keeping the school clean; it’s considered a way to teach cooperation, discipline, and responsibility.
School Lunch
In elementary schools and many junior high schools, kyuushoku (school lunch) is part of the daily schedule. Students serve food to each other on a rotating basis, then clean up afterward. Lunch is seen as part of education, encouraging healthy eating habits and teamwork.
Chime
Classes begin and end with the famous school chime: “keen-kong-kan-kong.” Almost everyone in Japan remembers this sound. It signals students and teachers to move promptly to the next activity.
Schedule Substitution
Because of school events or even typhoons, schedules may be switched around. For example, on a Wednesday, students might follow the Monday timetable. This flexibility allows schools to balance classes and activities across the year.
Exam Schedule
During exam weeks, the timetable looks very different. Each test usually lasts 50–60 minutes, and school often finishes by lunchtime. There is usually no school lunch, and students go home early.
Break Time
Between classes, there is a short break of about 10 minutes. Students quickly use the restroom, chat with friends, or get ready for the next lesson. The lunch break is much longer—45 to 60 minutes—allowing time for eating, relaxing, or preparing for club activities.
Now You’re Ready to Work in a Japanese School
In Japanese schools, the timetable is not just about classes—it also includes homeroom, cleaning, and lunch. Once you understand the meaning of koma, it becomes much easier to follow conversations about schedules and teaching loads.
At first glance, Japanese schools seem very strict about time. But in reality, schedules often change due to events, weather, or exams. Flexibility is just as important as punctuality.
Get used to this rhythm, and you’ll find it easier to connect with teachers and students, while also experiencing a key part of Japanese school culture.
Now you’re ready to work confidently in a Japanese school.