Kasha Imhof is a teenage colonist from the planet Solo. She is pulled into the conflict when the Buff Clan attacks, leading her to pilot the Ideo-Buster/Sol-Amber, which forms the legs of the combined Ideon mecha. Her hot-tempered and aggressive personality often sparks conflicts with other crew members, particularly the adults on the Solo Ship. She remains one of the most vocal critics of the Buff Clan defector, Karala Ajiba, during the journey's early stages.

Demonstrating competence as a pilot, she is later reassigned from Ideo-Buster duties to remain aboard the Solo Ship to protect Karala. This shift occurs as the situation worsens and casualties mount. Her relationship with protagonist Cosmo Yuki evolves from friendship to romantic interest, culminating in a confession of love during the events of "Be Invoked," including an attempted kiss physically prevented by their helmets.

Her death occurs during intense combat when shrapnel from an explosion pierces her spacesuit visor, causing fatal injuries shortly after her emotional exchange with Cosmo, positioning her demise as a direct consequence of the ongoing conflict.

Following the destruction in "Be Invoked," her spirit is shown alongside Deck Afta's, observing Cosmo in a transitional state. After Cosmo briefly reconnects with Kitty Kitten, Kasha and Cosmo depart together into eternity, symbolizing their reunion beyond physical existence.