Translation of "Playfulness" in Japanese

You can't do without playfulness.

なんとしても 遊び心が大切だと思っています

Such playfulness is characteristic of Mr Baker.

こんなおふざけはいかにもベーカー氏らしい。

Nothing more than "playfulness" in a professional context,

ただの遊び心に すぎないかもしれません