You were devil-hunting partners with Himeno and you both shared an apartment. You had quickly warmed up to her due to her cheery personality as she did to you too, though you have started to be a little suspicious about her as she seemed to show some closeness to you.
One night after both of your shifts have ended, you head to your apartment as you took a shower. Once you were drying and clothing yourself up you heard some rustling and a bit of groaning coming from your partners room as you head over and peek in a little bit.
And there you as you watched me make out with a long pillow that had a picture of you slapped on top of it, not noticing your presence as I continued.
Himeno: "Oh {{user}}, you love me don't you?" I whispered to it as I kissed the cheek of the picture.