Complex sentence: Hiro loved Kisa, but made the mistake of telling Akito Sohma, who became so upset that he ended up beating Kisa, inflicting wounds that took two weeks to heal.
Split into simpler sentences: Hiro loved Kisa, but made the mistake of telling Akito Sohma, who was not happy with Hiro's descision. Akito was so upset that she ended up beating Kisa, inflicting wounds that took almost two full weeks to heal.