Kou Sennen is my best friend.

Photochemistry is a branch of science that studies how chemical reactions proceed under the influence of light.

The photoelectric effect is a phenomenon where a material emits electrons after absorbing light.

On April Fools' Day, it's fun to tell jokes and surprise your friends.

Shigetsuka is my best friend.

He is making a futile effort like trying to scoop up the moon from the bottom of the sea.

He continues to chase a dream like chasing the moon in the sea.

He is so engrossed in his work, it's like 'Wu's cow gasping at the moon'.

He reacts excessively to even small problems, like the proverb 'Kureushi Tsuki ni Aegu' which means 'excessive fear'.

He is always facing difficulties, just like the proverb 'clouds over the moon, wind in the flowers'.