KOKORO has the questions on the all characters in the 3rd chapter. This paper choose two questions on the 3rd chapter: (1) Why did K commit suicide? (2) What did the last sentence mean, scribbled in K's suicide note? In understanding of KOKORO the most important character is that Sensei who is the narrator of this novel is incomprehensible K's mind, so the story told by Sensei is far from the truth. This paper's answer is below: (1) K determined to abandon the pursuit of his "Michi" and to give priority for the love to Shizu. And K trusted Sensei should support his decision. But Sensei denied K's decision instead to support. So his despair made him to commit suicide. (2) The last sentence is that "I should have killed myself early, but why I did not scuiside then?" K wrote this sentence to complain of Sensei and Shizu's engagement. Because their engagement told K that Shize had loved Sensei. And K notify that his determination to abandon the pursuit his "Michi" was made by his illusion that Shizu had loved him.