Kyou, Sekai Ichi no Kokuhaku wo.

From Batoto Scans :
A ‘confession’ is that moment when you become special to the person you love...

“It’s not a Special Confession” - Valentine's Day with a classmate.
“Deciding not to Confess” - I decided not to confess because I want to be with you.
“The End of Summer and the Missing Confession” - Reuniting with the person who confessed to me a long time ago.
“The Confession was made after a Happy Ending” - I confessed my feelings for the third time, and we ended up going out, but...

A collection of 4 short stories about pure confessions from each season!

Note: The series was first published under the title "Kimi ga Suki tte Iitai" in Dessert Pink.