One-Track Mind
Single Mindedness
noun, な adjective
You have only one book energy. No other books cross your mind. Only this one book. Why? Because you have such a one-track mind.
The reading is based off the on'yomi readings for everything, though every reading is slightly altered. いち getting shortened to いっ, ほん changing to ぽん, and き gets changed to ぎ. They're based off the readings you know already, though, so making this shift shouldn't be too hard... that is, unless you have an 一本気, ammiright?
一本気の人
a single-minded person
一本気の男
a single-minded man
一本気のサムライ
a single-minded samurai
ニックって一本気なところがあるよね。
There's a single-minded side to Nick.
コウイチは一本気な男だ。
Koichi is a man with a one-track mind.
おじいちゃんは、百才になった今でも、おばあちゃんのことを「オレの大切な女」ってよぶんだ。ほんと一本気な男だよ。
Even now at the age of a hundred, Grandpa still calls Grandma "my precious woman." He's such a one-track-minded man.