Shape of Happiness

Original title: 幸せのカタチ　外野の恋　番外編

Souta and Doumoto have finally moved together. However, the couple's happiness is short-lived since Souta's older sister, Kozue, unexpectedly goes to her brother for asylum after arguing with their parents and running away from home. Souta will end up developing jealousy towards her sister since he believes Doumoto is interested in her.