Kaoruko Yanagida is a pink-haired, pink-eyed second-year high school student and the goaltender for the Nikko Dream Monkeys ice hockey team. Initially shy and reserved, especially in expressing her feelings, she joined the position after friends nominated her based on brief soccer goalkeeping experience, quickly discovering its greater demands. Her quiet determination fuels rigorous training as she hones skills like puck tracking and shot anticipation.

Longtime friends with Manaka Mizusawa, Ayaka Mizusawa, and Mami Ono before hockey, she explored the sport alongside them in a trial class. When Mami transferred schools early on, Kaoruko remained with the team alongside Manaka and Ayaka. Her reserved nature hindered on-ice communication, identified by Coach Yoko Matsunaga as a key area needing improvement.

A pivotal moment occurred during a team trip to Okinawa. Playing beach volleyball highlighted her communication struggles, leading to Manaka's observation about Kaoruko's calming presence needing vocal support. This prompted Kaoruko to consciously work on expressing herself. Her resulting growth directly improved her goalkeeping; better communication allowed her to coordinate defensive plays and direct teammates more effectively during games. Trusted by teammates like Manaka and Ayaka, her journey emphasizes gradual technical improvement alongside developing vocal leadership.