80% of this fandom is yaoi, since there are very few female characters in the series. Also, most of the primarily GOOD fanfiction is on Live Journal. Katekyo Hitman Reborn! serializes in Shonen Jump! weekly but translations come out late most of the time. The main character is Tsunayoshi 'Tsuna' Sawada, a boy who is bad at academics and sports. He meets an infant hitman Reborn who later becomes his tutor, as Tsuna is to be the tenth boss of the Vongola family.
This manga is also interesting because it uses numbers in response to the character's names. For example, Tsuna is 27 because tsu= 2 and na= 7. Something like that. All in all, Katekyo Hitman Reborn! is decent for a manga. Although the fanbase is mostly made up of avid fangirls, the characters are memorable (and hot, even) and the antagonists are quite cool.
P.S. the Arcobaleno arc is a filler, SO STOP FUCKING ASKING IF THE MANGA AND ANIME WILL GO DIFFERENT WAYS NOW.
Random Fan: Oh Jesus. Someone get a horse tranquilizer here, stat.
Jerry thinks that Katekyo Hitman Reborn! has way too many obsessive, yaoi, stalker-ish fangirls.