[Completed after 6 years hiatus] Yumi and Sachiko are married to each other but they face problems just like any married couples do. Would they resolve their issues before it's too late for regrets, or will something else happen?

Sachiko invites Yumi to town to check out a new department store that recently opened, which has seven floors. It's a new store, so the elevators and such are in perfect working order, right? Wrong...

[SachikoxYumi, YoukoxSei] Sachiko asks her oneesama and Rosa Gigantea to deliver a very important letter to her petite soeur on the day after her wedding... but they weren't ready to wait until it was too late. Is Yumi? ...