Complex sentence: Isshiki actually does not know how to swim.On the last chapter he decided to go to college and live on his own.On the last chapter, he said that when he is strong enough he will find Hina.
Split into simpler sentences: Isshiki actually does not know how to swim.In the last chapter he decided to go to college and live on his own. Also, in the last chapter, he said that when he is strong enough he will find Hina.