Meaning of Mental Tofu (メンタル豆腐)

“Mental tofu” means sensitive.
Do you know tofu? It’s crumbles easily.
So “Mental tofu” means “my heart is like a tofu, my heart is fragile”
You can also say “I have a tofu mental”.

Example Conversation

A: Why don’t you ask her to be my girlfriend?
B: I can’t, my mental is tofu.

A:彼女に付き合ってって言ったら？
B:できないよ。俺、メンタル豆腐だし。