Ai-chan was also an addition to the anime, and the framing device of Akari sending emails to her replaced the more generic blog entries of the manga. It worked well enough that Ai ended up as a Canon Immigrant to the manga later, and a featured character in later instalments like #ARIAtheAVVENIRE.

https://tvtropes.org/pmwiki/pmwiki.php/CanonImmigrant/AnimeAndManga

#ARIAtheANIMATION