Complex sentence: For much of the series, he nurses a fairly obvious crush on Tiffa but does not act, fearing that the Tiffa would be unnerved by his advances, since she was denied most of her childhood.
Split into simpler sentences: For much of the series, he nurses a fairly obvious crush on Tiffa but does not act. The reason for this is he fears Tiffa would be unnerved by the unfamiliar situation, since she was denied most of her childhood.