Complex sentence: At the beginning of the series, Souma has feelings for Kureha, despite knowing that she has feelings for Kiriya; he sometimes gets annoyed at Kiriya for not noticing her feelings for him.
Split into simpler sentences: At the beginning of the series Souma had feelings for Kureha, despite knowing that she had feelings for Kiriya. Souma would sometimes get annoyed at Kiriya for not noticing her feelings for him.