Summary
From HotCakes:
The man super-uptight office worker Ooizumi Sonoko got drunk and spent the night with shows up at her work and turns out to be the section chief?! A hilarious romantic comedy about pure love wrapped in indecency.
This series was published as part of vol 2 – 5 in Oboretai and the first 3 chapters(done by ShoujoMagic) can be found in vol 2.