Takahira-san no Ongaeshi

When Takahira met Hinata in high school, she was determined to repay Hinata for when he protected her from bullies when they were little. But Takahira's habit to repay all favors is extravagant and out of control! It doesn't help that Hinata is a naturally helpful person, so now they're caught in an endless favor and gratitude loop!