Marisa: Reimu, do you sure you've beaten Yuugi before?
(stares at the sin-sack)
Reimu: Yea. Why did you ask...?
(Marisa stares at Reimu's chest, compares it to sin sack's-head, then nods.)
Marisa: Im's sure it's the hitbox size.

That would only happen if Yuugi did it on purpose.

Agreed, the result if Yuugi didn't slap him on purpose would more... messy...

No, no. See, Yuugi's talent of fighting without spilling sake indicates a fine motor control. This means that she only exerts herself as much as she wants to and only as much.

And considering how she's almost assuredly drunk at any given time, involuntary movement might not apply to her. She wouldn't crush anyone unless she intended to crush them.

She could have just overestimated who she was slapping

she just playing around woth you

Amazingly I dont see sake.

shadowninja said:
Amazingly I dont see sake.

well that explains it she's sober

Is Yuugi less strong than Yuuka?

potatotomato said:
Is Yuugi less strong than Yuuka?

She's holding back.

potatotomato said:
Is Yuugi less strong than Yuuka?

Physically? No.

Physically I think Yuugi is the strongest. Then Suika, Kanako, Yuuka. Flandre is a glass cannon.

ryuukami123 said:
well that explains it she's sober

Yep. She's got great control when drunk, but loses it when sober.

shadowninja said:
Amazingly I dont see sake.

That's because she already drank all of it.

potatotomato said:
Is Yuugi less strong than Yuuka?

Yuuka seems to be slapping for sadistic pleasure seeing how she's smiling calling the Sin Sack you "scummy little troll"
Yuugi just seems like she did an Oh U! kind of slap thinking the sin sack was joking around with her, also she seems to be laughing to.