When a person reacts lightly or barely to a piece of work (art, music, stories). It typically includes dry responses to works of art or things people would like more of a reaction from.
Yumi is a dream entity that visits people's dreams every month or week, she is the only dream entity to be not hostile towards BF so far, and is very much liked by GF for what she can do.
"Yumi The Dreame is someone who makes your dreams come true, inside of your dreams!"