He started a business without a plan, forgetting the lesson of 'peach and chestnut seeds take three years to bear fruit, persimmons eight years.'

He learned a big lesson from that failure.

He taught me an important lesson.

I forgot his birthday.

I decided to start a new project.

He came to Japan for the first time.

Since I started studying Japanese, I have been able to understand more about Japanese culture.

He started playing the piano.

We are planning to start a new project.

He is my best friend.