- "I love my big sister, and I just know she loves me back!" 
Chiko Sekino (関野 チコ, Sekino Chiko) is a Cream Anmitsu idol unit member in Dropout Idol Fruit Tart.
She has waist-length plum colored hair that is tied in a big side bun by a black cloth with short square bangs hanging over her eyebrows and matching colored eyes. She also wears a violet checkered shirt, a red tie, a midnight blue skirt with white trim, black stockings and red shoes.
Chiko is the fifteen year-old little sister of Roko, and a classmate of Hemo. She performs as a member of Cream Anmitsu, an idol group produced by Riri Higashi of Cat Productions, alongside fellow members Nua Nakamachi and Rua Nakamachi. On top of being an adept swimmer, Chiko also has experience in voice acting and "secretly" stars in her sister's favorite cartoon show. As highlighted in the group's 55-minute variety show, Anmitsu Academy, Chiko is a D-cup.
In the eyes of her fans, Chiko can be seen as being very mature for her age, which stands in sharp contrast to her loud, clamorous sister. While younger than Roko, given the 24 centimeter (9 inch) difference in stature between them, Chiko tends to act as the dominant sibling, often teasing Roko and treating her like a child. Despite such treatment, deep inside Chiko has nothing but love for her older sister, having admired Roko so much during their childhood that she once imitated her unique hairstyle - subsequently removing one bun out of respect. Now as idol performers, Chiko does everything she can to support her sister from the sidelines.
However, Chiko's concern for her sister can be seen as being slightly overprotective, with her watching over Roko at times from a distance and without her knowledge.
- Chiko's surname Sekino means "barrier, gate" (関) (seki) and "field, wilderness" (野) (no).