Complex sentence: Even then, though, he cannot find the courage to confess to her, frightened that she will not return his feelings; however, upon hearing Haruhi's confession, he admits his feelings and the two become a couple.
Split into simpler sentences: Even then, he cannot find the courage to confess to her, frightened that she doesn't return his feelings. Then, upon hearing Haruhi's confession, he admits his feelings and the two become a couple.