Less romantic but more plausible: This is a used by bots or human spammers to bypass keyword filters and push fake software or malicious downloads. The phrase appears in the comment sections of old Madobe Nanami (Windows 7 OS-tan) videos and some Nico Nico Douga MMD (MikuMikuDance) clips.
Locate the downloaded .apk file in your file manager and tap it. uchi no otouto maji de dekain dakedo mi ni kona install
If the content you're trying to access is in Japanese and you're not familiar with the language, you might consider: Less romantic but more plausible: This is a
The main cast includes Nao (the brother), Chiaki (the sister), and her two friends, Nagisa and Yukiko. Is there a Game to Install? Chiaki (the sister)