The 18-year-old says he is happy to be patient while he continues his footballing education.
"I am not in a rush," Miyaichi told arsenal.com. "The manager advises me not to and to concentrate on training.
"The biggest change is that I train and play with these top players. I never imagined myself in this position a year ago when I was playing in the high school championship qualifiers in Japan.
"I can tell I am improving a lot through training sessions with my team-mates. I am also getting used to expressing myself to them without hesitation.
"I felt quite positive when I dribbled pass those international players in training sessions. I have confidence in myself to a certain extent as I train with these world-class footballers."
"I was too shy and nervous when I first joined the team. Now I feel more settled living in this environment. Arsenal found an English teacher for me. I suppose I am improving, I can understand what the coaches say."