Thanks for the chapter TulipMoon! Being a grammar stickler just because you asked for it
"I'll Going!" (p5) should be "I'll go!". The "-ing" form of verbs is an adjective - "I'm going!" could also be grammatically correct, but you'd generally only use it if you had already agreed to go and are reaffirming it.
"Enjoy the time" (p6) may be better served by the idiom "Take your time"
"Come closer" (p11) is generally used if you want somebody to get *very* close (sensually, because of hearing problems, so you can smack them, etc). "Come over here" might be a better fit
"Already clean the beds" (p13) is missing its subject. Should this be "I've already cleaned the beds"?
"yes, al-san?" (p14) generally means "what do you want, al-san?". "right, al-san?" may be a better fit
"I also join in" (p15) sounds like she's telling a third party about their habits, rather than offering for this particular instance. "I'll also join in" would probably fit better.
"The bed that I prepared for a long time" (p16) sounds a bit stilted ("The X that I Y'd for Z" usually means that Z is the purpose of Y). "The bed that I spent such a long time preparing" (or "... so long preparing") may fit better