Blue Box Graphic Novel Volume 10

After a hectic shopping date, Taiki takes Chinatsu to watch a beautiful sunset. With this perfect atmosphere, Taiki is preparing to tell her something important-when he's interrupted by Chinatsu's former teammate! The venom Yumeka unleashes on Chinatsu leaves Taiki stunned. Who exactly is Yumeka, and what ruined her seemingly unbreakable friendship with Chinatsu?