Kyoko Todoyama is the energetic and delusional president of Ebisugawa Public High School's Astronomical Club. She propels eccentric activities and experimental initiatives within the club, driven by impulsive reactions to anything she finds intriguing or entertaining.

She persistently targets fellow club member Hakata Kanamori for unwanted physical attention, including repeated stripping. Kyoko also demonstrates manipulation, coercing new member Itsuki Noya into crossdressing to retain membership under a fabricated all-girls club policy. She devises unconventional tests for potential members, often unrelated to astronomy.

Kyoko treats club activities as personal experiments, branding them as investigations into phenomena she invents or exaggerates. She exhibits hostility towards external interference, particularly opposing student council president Yuka Iseda over club abolition threats. Her relationship with her younger sister, Izumiko Todoyama, is competitive and conflict-ridden, frequently escalating into quiz battles about club matters.

Specific preferences integral to her daily club routines include konpeito (star-shaped sugar candy) and incense. She frequently initiates chaotic parodies of popular anime and tokusatsu series during club time.

Her established traits and behavioral patterns remain consistent throughout all official media appearances.