Tsukishima Marina functions as an in-game navigation character and staff member at the live house CiRCLE, coordinating multi-band events and supporting the formation of five bands for collaborative performances. She has black hair in a shoulder-length bob cut, fair skin, and brown eyes. Her typical attire includes low-cut jeans, a white-and-blue horizontally striped shirt, and a black cardigan. Marina displays a friendly, hardworking, and down-to-earth personality. She enjoys reading manga and dislikes horror or scary elements. Her backstory involves playing guitar in a five-member band during her youth, which disbanded after losing both their audience and passion. During their breakup, the band created the song "HOPE," recording and distributing it to friends and fans. Marina cherishes memories of this creative process, occasionally humming the tune while working. She stores her guitar backstage at CiRCLE and plays it intermittently. In the mini-anime series *GARUPA☆PICO ~Ohmori~*, Marina appears more frequently, serving as a comedic foil to the main bands. She introduces bands with dramatic flair in the first episode and experiences recurring physical humor due to CiRCLE's chaotic situations. Her involvement includes participating in staff initiatives like customer-attraction conferences to revitalize the venue. Marina stands 157 cm tall, matching the height of several main characters. She is the franchise's only major adult character who is both prominently featured and voiced, contrasting with other minor adult supporting figures. Appearances beyond the initial main story chapters remain infrequent in event stories, card stories, and later band narratives. Her background as a former musician underscores her dedication to helping younger bands pursue their dreams.