Koi wa Misoji wo Sugite kara

Sakura Uehara, who is 30, has been so devoted to work that she hasn't even dated since high school. Not able to go to university, she went straight to work, and was determined to show everyone she is just as good as those "college assholes" the company values so much. After 12 years in the same company, she has risen to department head, and as luck has it, one of those same college assholes is assigned under her. Yamada is good looking, talented, and on the fast track to success - and destined to be promoted right past her. Of course she ends up hating him.
Letting her pride get the better of her, she takes on an assignment on a tight deadline and has to work late into the night. When a blackout makes her lose her data, she's blows her cool and melts down herself, knowing that there's no way she can make the deadline now. Of course, that's when Yamada comes along, and the two of them working together manage to make it in time. When Sakura tells Yamada she owes him one, he quickly asks to be paid back by having her go out on a date with him. Soon she finds herself in a love hotel with the very asshole she hates so much, but does Yamada have the right stuff to get past her tough exterior and touch her heart?
(Source: Mangahelpers)Included one-shots: Boku ga Seifuku ni Kigaetara, Ohikkoshi Bugi