- Name: Oba Sayaka (大場紗也加)
- Nickname: Oosaya (おおさや)
- Birthdate: March 11, 1998
- Birthplace: Kanagawa, Japan
- Blood Type: O
- Height: 151cm
- Hobbies: Traveling, reading essays, harnessing information on beauty
- Specialties: Using a cash register quickly, travel coordinates, piano
- Bands / Groups:
- She had her official debut as a ninth generation Kenkyuusei member on December 31, 2018 at the SKE48 theater. She withdrew from the group on May 13, 2019.
- Her favorite colors are light pink, monotone, gold, and silver.
- Her future dreams are to be a mystery hunter, appearing on a wide show or a traveling show, and writing an essay.
- Her favorite foods are seafood, strawberries, crispy foods, hamburgers, and shabu-shabu.
- Her favorite words are "aisareta kereba, mazu anata ga aishinasai" (愛されたければ、まず貴方が愛しなさい).
- Her message is "I think that song/dance inexperience, the starting point from the age of 20 is a minus point, but do not take your eyes off me as I will do my best to be positive!" (歌・ダンス未経験で、20歳からのスタートという部分がマイナスポイントだと思いますが、プラスになるよう精一杯がんばるので目を離さないでください！)