Whoever beats another person or intentionally injures another person’s body shall be detained for 5 to 10 days and fined ¥500 to ¥1,000; where the circumstances are relatively minor, detention of up to 5 days or a fine of up to ¥1,000 applies.

Under any of the following circumstances, detention of 10 to 15 days plus a fine of ¥1,000 to ¥2,000 applies:
(1) Beating or injuring others as a group;
(2) Beating or injuring a disabled person, a pregnant woman, a person under 14, or a person aged 70 or above;
(3) Repeatedly beating or injuring others, or beating or injuring several people at once.

(Update: this is Article 51 of the revised Law, adopted 27 June 2025 and in force from 1 January 2026 — formerly Article 43. Fines were raised across the board, and the aggravating age threshold changed from 60 to 70.
Note: bar fights and street altercations can lead to administrative detention even with no serious injury, and a detention record may affect a foreigner’s visa renewal. A foreigner may additionally be ordered to leave within a time limit or be deported (Article 10). New Article 19 adds a self-defence rule: stopping an ongoing unlawful attack is not itself a public-security offence.)

殴打他人的，或者故意伤害他人身体的，处五日以上十日以下拘留，并处五百元以上一千元以下罚款；情节较轻的，处五日以下拘留或者一千元以下罚款。

有下列情形之一的，处十日以上十五日以下拘留，并处一千元以上二千元以下罚款：
（一）结伙殴打、伤害他人的；
（二）殴打、伤害残疾人、孕妇、不满十四周岁的人或者七十周岁以上的人的；
（三）多次殴打、伤害他人或者一次殴打、伤害多人的。

（更新提示：本条为2025年6月27日修订、2026年1月1日起施行的新版《治安管理处罚法》第五十一条，原第四十三条。罚款额度整体提高；加重情形中的年龄标准由“六十周岁以上”改为“七十周岁以上”。
注：酒吧冲突、街头斗殴即使未造成轻伤，也可能被行政拘留；行政拘留记录可能影响外国人的签证续签。对违反治安管理的外国人，还可附加适用限期出境或者驱逐出境（第十条）。新法第十九条新增正当防卫条款：为免受正在进行的不法侵害而制止，造成损害的，不属于违反治安管理行为。）