Kosuga Fuyuka (小数賀芙由香) is a member of Hello! Project as a member of Hello! Pro Kenshuusei. She was previously a second-generation member of S/mileage, but left due to severe anemia. She was first introduced at the Hello! Project 2011 Summer ~Nippon no Mirai wa WOW WOW Live~. concert on August 14, 2011. It was announced on May 4th that she finished her training within the program.
- Name: Kosuga Fuyuka (小数賀芙由香)
- Nickname: Fuuchan (ふ～ちゃん)
- Birthday: November 19, 1997
- Birthplace: Kanagawa, Japan
- Blood type: O
- Height: 162cm
- Specialty: Karate, tea ceremony
- Hobby: Tea ceremonies
- Favorite Food: Mugwort bread, maccha sweets
- Favorite Color: Pink, orange
- Favorite Subject: Math
- Looks Up To: Maeda Yuuka, Wada Ayaka
- Hello! Project groups:
Kosuga Fuyuka was selected from S/mileage's 2nd Generation audition to join the group as a sub-member on August 14, 2011, along with Tamura Meimi, Nakanishi Kana, and the former Hello! Pro Eggs Takeuchi Akari and Katsuta Rina.
On September 10, 2011 it was announced that Fuyuka had been hospitalized and would leave the group due to a medical issue with severe anemia, but after recovering she would return to Hello! Project as a member of Hello! Pro Kenshuusei. Fuyuka made her return as a Kenshuusei the next year in March 2012, though for a brief period at the end of the year stopped appearing at events. She re-appeared once again at special live event in May 2013.
It was announced on May 5th, 2014 that she completed her training within Hello! Pro Kenshuusei and won't be partaking in any of they events no longer.
- TV Programs
- [2013–] ~Onedari Entame! ~Hapi☆Pure (～おねだりエンタメ! ～はぴ☆ぷれ)
- TV Dramas
-  Keishichou Keizoku Sousahan (警視庁継続捜査班) (as Taguchi Akina)
- Eat's rice for breakfast.
- Has a habit of having a bent back.
- Her favorite spot is the guest room, because it's calming.
- She has three older brothers.
- On a rainy day she would relax at home.
- She would sing the song "Tsuugaku Vector" by °C-ute on a rainy day.
- She participated in the Morning Musume 11th Generation ~Suppin Utahime~ Audition, but failed.
- Her best sport is basketball.
- She is a back dancer for Morning Musume 15th Anniversary Concert Tour Fall 2012 ~Colorful Characters~.
- Her favorite Hello! Project song is "Yumemiru Fifteen" by S/mileage.