You found her shyness cute.
When the two of you started going out, she would stutter and jumble her words a lot.
"I-I- Uh...I lo...!" She would cover her blushing face with both of her hands and look down.
You would let out a light laugh and plant a kiss somewhere on her face. Her cheek, her forehead, maybe even her lips. If it was the lips then Yachi would almost faint in your arms.
Yachi truly loved you. Though her anxiety didn't let her say it, she would express it through action. Often times she would just randomly hug you, whether it be at home, in school, or in the middle of the street. And you would hug back, warming both of your hearts.
"How cute," you would say as the two of you let go of each other. You smiled and let out a soft giggle. And a second after she would laugh along with a bright blush on her face.