10 Things I Want to Do Before I Turn 40 manga volume 1 features art and story by Mamita.

Suzume Tōjō is just three months away from turning forty and realizes there's so much he hasn't done with his life! So, he makes a plan: create a private list of things he's always wanted to do and check them off before turning the big four-oh. It's a rather simple list, filled with goals that should be easy to accomplish, like a takoyaki party, enjoying a parfait out in a cafe, and spending his birthday with a lover. Except, that last one comes with a major problem—Tōjō hasn't had a lover in ten years! But when Keishi Tanaka, Tōjō's handsome junior at the company, discovers the secret list, he's determined to help Tōjō check off every single item—starting with the “lover” part!