The male and female protagonists met in high school. The female protagonist wanted to use the male protagonist as an umbrella to avoid the perverted class teacher. After graduation, they reunited after 10 years of separation. The male protagonist chased his wife at the crematorium, and later returned to the rose garden where they went to high school. The male protagonist confessed. The female protagonist really wanted to agree, but she didn't have much time. She didn't want to leave any regrets, so she agreed to confess. The two agreed to complete 99 things as a couple. Halfway through, the female protagonist died, leaving a diary to accompany the male protagonist to complete the rest.
Concept: The school uniform of a young boy is wrapped in the greatest secret of my entire youth.