| Oin Junior and Senior High School | |
| Native Name: | 桜蔭中学校・高等学校 |
| Latin Name: | Schola Media et Summa Oinensis |
| Mottoes: | 勤勉 ・温雅 ・聡明であれ 責任を重んじ、礼儀を厚くし、よき社会人であれ |
| Motto Translation: | Diligence, refinement and intelligence Respect for responsibility and an unfailingly courteous manner make for good citizens |
| Location: | 1-5-25, Hongo, Bunkyo, Tokyo, Japan |
| Postcode: | 113-0033 |
| Fundingtype: | Private |
| Established: | 23 April 1924 |
Oin Junior and Senior High School (桜蔭中学校・高等学校) is a private girls' school located in Hongo, Bunkyo, Tokyo that provides six-year secondary education programmes.
The school was founded in 1924 by members of the alumnae club of Tokyo Women's Normal School, Oin-kai (櫻蔭会). The first principal of the school, Kikuno Gokan (後閑菊野), had been responsible for the education of Empress Kojun, and she placed focus on manners in the creation of Oin as well.[1]
Oin is known as one of the most selective secondary educational institutions in the country, and is one of the largest sources of successful applicants to the University of Tokyo, which is usually regarded as the nation's most selective and prestigious university.[2]
| Kaisei | Private boys’ school | 149 | |
| Seiko | Private boys’ school | 100 | |
| Nada | Private boys’ school | 94 | |
| Komaba (Tsukukoma) | National boys’ school | 90 | |
| Nishiyamato | Private coeducational school | 71 | |
| Shibuya Makuhari | Private coeducational school | 64 | |
| Oin | Private girls’ school | 63 | |
| Hibiya | Public coeducational school | 60 |