あぁいぃうぅえぇおぉ – How to Type Small Vowels in Japanese
You don’t need a special Japanese keyboard to type in Japanese! You can type small Japanese vowels or any characters on a keyboard after you install Microsoft IME Japanese for a PC or add Japanese with your Mac. In order to type small vowels, you type x or l just before the character.
INDEX
l or x before any Vowel
You can actually type all small characters by proceeding them with l or x. So, 「ぁ、ぃ、ぅ、ぇ、ぉ、ゃ、ゅ、ょ、ヵ、ヶ、ゎ」could be types like la, li, lu, le, lo, lya, lyu, lyo, lka, lke, lwa” or “xa, xi, xu, xe, xo, xya, xyu, xyo, xka, xke, xwa.
https://japaneseuniverse.com/2024/02/18/pac-man-in-japaneseconcepts-behind-development-to-global-icon/Foreign Loanwords
Also, anything you are typing a foreign loanword in Japanese that has a sound that is not in native Japanese words you can usually just type the vowel as is following the consonant. For example office in Japanese is オフィス. You just time fi and you get the small i.