Please help

I cant seem to find a story

The story gos like this...

Kyoko and Ren or Kuon (Can't remember which) are newlyweds

They are staying at Ren's apartment

Kyoko woke up the next morning, Ren cannot be found, no food in the apartment so she went out

When she's about to go back she realized she doesnt have a key so she was forced to stay outside the apartment building

When Ren came back to his apartment, he cannot find Kyoko

Please help me out