Kowamote Kouhai ga Ichinichi Ikkai Suki tte Ittekuru

Every day, Haru Inui (27) goes hard in both her personal and professional lives. And every day, her boyfriend tells her that he loves her. Those words alone give Haru the strength to work hard—until the day she discovers that her boyfriend has been bringing other women to her house when she isn't around. How could she have believed his simple "I love you"s?! Haru feels like an idiot... when suddenly, her junior at work, Okuma, tells her that he has feelings for her! Determined to win her heart, Okuma promises to tell Haru, who doesn't believe in those three little words anymore, that loves her once a day, every day. Seemingly aloof, Okuma turns out to be unexpectedly bold! Haru doesn't know when, and she doesn't know where, but Okuma's surprising daily "I love you"s quickly turn into the office romance she didn't know she needed.

(Source: Coamix)