This is a story shortly before they were locked up.
They went into a storeroom on an adventure, and the three of them are exploring various things.
Mika tries to leave, but Kachusha finds something golden and decides to stay.
Mika-chan is conflicted.
Kachusha-chan's hand slipped and the toy almost hit Mika-chan. But Calvados protected her.
Mika-chan seems to have fallen in love with her coolness.