Rakuten travel assured me that “Oh just put both your first and middle name in the first name box. It’s fine” and now I have by boarding pass, which even drops the capital for the middle name and I’m really worried? Rakuten did not allow the space at all but the 20,000 yen cheaper ticket felt good at the time.
Edit – appreciate the variations of "its fine/normal/stop worrying. I feel less worried now.
by link6616