Complex sentence: Yahiro eventually gives up his feelings for Akira, telling Tadashi that if he ever makes Akira cry, he will never forgive him, but knows that Tadashi would be better for her.
Split into simpler sentences: Yahiro eventually gives up his feelings for Akira, telling Tadashi that if he ever makes Akira cry, he will never forgive him. Yahiro soon gives his feelings up for Akira and knows that Tadashi would be better for her.