An old person was walking in the park.

Tetsuro is my best friend.

Ryuichiro is my best friend.

He is working hard to support his family.

He is known as an expert in gerontology.

He was diagnosed with tabes dorsalis.

Let's play the Werewolf game with friends tonight.

My grandfather is interested in gerontology.

Many workers are working in this factory.

My grandmother lives in a nursing home.