GETSUYOUBI NO TAWAWA

A salary man is quite depressed, especially on Mondays. At his lowest point a well-endowed High-School girl calling herself Ai-chan stumbles breast-first into his face. The concussion she gave him served as the start of their relationship. Features additional single-page images of other side-stories, that were posted on the Authors Twitter every Monday before. The first volume illustration compilation book that also includes comic was released on December 31, 2015 at Comic Market 89. The second volume was released at Comic Market 90 and the third volume was released at Comic Market 91, all has been published by Himura himself. — Description from AniList community (anilist.co).