From ShoujoHearts:

Tomonaga Kairi is the top student in his year and and a skeptic when it comes to the universe. But one day, he accidentally gets involved with the eccentric Nanbu-senpai, president and the only member of the Space Research Club. What will happen to Tomonaga when she tries to get him to join her club before it gets abolished...!?

From LemonadeScans:

Kisaragi Maaya, 16 years old. The first love confession of her life was a complete rejection. She vowed to "never confess to someone again" until one day, the popular Chigira-kun who was on library duty with her, in order to heal his wound of unrequited love, proposed to her that they "heal each others broken hearts"! Everyday, being healed by Chigira-kun, Maaya starts thinging that she want to be closer... But, this is just comforting each other's broken heart. Even though she definitely can't fall in love with Chigira-kun-!!?