The main character(Takemoto) is actually more of a background character in S2.
In S1, Takemoto rediscovers himself.
In S2, after confessing his love for Hagu, he realizes... no, he probably knew beforehand, that he can't be with Hagu, because he knows that Hagu loves Morita.
But knowing that Morita has given up on Hagu, he feels a strange relief, because despite of his strong friendship with Morita, he feels that Morita is not able to give to Hagu what Hagu needs.
But Takemoto is thankful that he had fallen in love with Hagu, because it made him understand how he wants to live his life.
He is thankful.