Kokoro is the soon-to-be girlfriend of Kippei. She is pretty, although quiet, and rather lonesome as she lost her mother at an early age of 6. This makes it easy for her to sympathize with Yuzuyu. Her father married another woman and thinking Kokoro could fend on her own, rents her a luxurious apartment to live in. The truth is, that is not the case. Kokoro is understanding of Kippei's responsibility to spend most of his time with Yuzuyu. Despite her popularity and Kippei's moron-ness, Kokoro's heart remains loyal to Kippei.