Hello Kitty no London ni Orita Uchuujin (ハローキティのロンドンにおりた宇宙人) Also known as Hello Kitty's The Aliens Who Came Down From London is a 29 minute OVA released by Sanrio on September 9th, 1992.
Plot[]
Kitty and Mimmy hear from their friends at school about recent UFO sightings in the area and one night goes to investigate one of the UFO crash sites themselves in order to learn more about both the spacecraft and the mysterious aliens that came with it...
Gallery[]
Source[]
https://myanimelist.net/anime/17953/Hello_Kitty_no_London_ni_Orita_Uchuujin
Hello Kitty's The Aliens Who Came Down From London (English Subtitles)