It is not uncommon for Japanese popular media to use double meanings, by writing the word in Japanese with one meaning and then giving it an English pronunciation with a different meaning.
Simply put, in the light novel series you are talking about, there is a character called "Accelerator" which is written as 「一方通行」 which is an expression used on traffic signs to refer to a one way street.
The name Accelerator alludes to the character's ability to be able to move the vectors in order to accelerate himself, while 一方通行 expresses that his power is like a one way street, because he can always change the direction.
Specifically regarding, 御手, it is used because most of the powers' names in the series are 4 characters long. In this context, 御手 has little to do with an actual hand, and more to do with an "ability", since a person's ability can also be said as their "hand" in Japanese.
Also, 巨乳 is not just a bust, but specifically a BIG bust.