KANJI GUIDE
弘める is to spread a teaching. The character in 弘法, the great teacher Kūkai.
The character in 武士道, the way of the samurai, and in 柔道. Read dō, and the head of it is taken for do.
The 曼 of 曼荼羅 — mandala. Chosen fifteen hundred years ago to carry a Sanskrit sound, not a meaning. Your name is being written the same way.