Uso ka Makoto ka

One day, Taiyou, a popular guy because of his good looks, was asked by a senior student at his part-time job to take care of his cousin, Tsukihiko, who is attending the same university as Taiyou. However, Tsukihiko is rude to him from the beginning to the end, Taiyou still tries to be lenient towards him, but on the inside, he's on the verge of exploding because of him! Suddenly, Tsukihiko confessed his feelings to Taiyou and took him to an empty classroom where he made his move...!

(Source: Core Magazine, translated)