になると

expression

when it becomes; when it comes to

Used to mark a condition or topic shift: 'when the situation reaches X' or 'when it comes to X'. Often follows a noun or clause.

• 春はるになると、桜さくらが咲さきます。

  When spring comes, the cherry blossoms bloom.

• 彼かれは仕し事ごとになると、急きゅうに真面目まじめになる。

  When it comes to work, he suddenly becomes serious.