Kasai (surname)
Kasai is a Japanese surname. Notable people with the surname include:
- Akira Kasai, Japanese politician
- Hisashi Kasai, Japanese ice hockey player
- Jun Kasai, Japanese professional wrestler
- Ken'ichi Kasai,, Japanese anime director
- Kenji Kasai, Japanese table tennis player
- Kenta Kasai, Japanese football player
- Kimiko Kasai, retired Japanese jazz singer
- Masae Kasai, former Japanese volleyball player
- Morio Kasai, Japanese surgeon
- Noriaki Kasai, Japanese ski jumper
- Tomomi Kasai, Japanese singer, actress and a former member of the idol group AKB48
- Yoshiko Yoshiizumi née Kasai, Japanese ski jumper
