Eiko Tsukimi hails from Kyoto. Her father's departure to pursue music in the United States triggered family strife, leading her mother to vehemently oppose Eiko's own musical interests and causing a lasting estrangement. Eiko blamed her mother for driving her father away, deepening their divide.

During a personal crisis, Eiko attempted suicide on railroad tracks, only to be saved by Kobayashi. He brought her to his nightclub, BB Lounge, where hearing American singer Maria Diesel perform reignited Eiko's hope. Inspired to move others with her voice like Maria moved her, Eiko began working at BB Lounge as a resident singer and store clerk.

When Eiko met Zhuge Kongming, she was close to abandoning her musical dreams. Moved by the emotion in her singing, Kongming became her strategist. Under his guidance, she gradually rebuilt her confidence and refined her skills. Her performances alongside rapper Kabetaijin played a role in his return to rap after a health-related hiatus and pressure. Similarly, a street performance encounter with Nanami Kuon, vocalist of Azalea, rekindled Nanami's passion for authentic musical expression.

Eiko's career advanced significantly with the founding of the record label "Fourth Kingdom," where she became the lead singer. Kobayashi, who had once worried BB Lounge might limit her growth, continued supporting her within this new venture. He later inspired her to create the song "Hot Chill Hot." Her journey traces a path from despair to artistic purpose, fueled by resilience and key collaborations.