Ouran Koukou Host Club, Fruits Basket Recommendations
Both series are mostly-friendship-based reverse harem shoujo series catalyzed by an important and series-enduring secretive element that provides as much drama as humour for the series. As both progress, the potential for drama and tears becomes clearer the more the reader gets to know about the characters' families. Some romance, some cuteness, and it turns out the series may be more similar than they seem at first glance!
Want to know what shōjo stereotypes Ouran pokes fun at? Then Fruits Basket is a must. Haruhi is the antithesis of Tohru sometimes, with her very stoic unemotional way of acting. Tamaki takes Tohru's "always smile" philosophy to a whole new extreme. The high school setting, the privileged families, the gigantic casts and backstories - even Momiji and Honey-senpai are unbelievably similar. The main couple are slow to realize their feelings, too. Ouran is a sillier answer to Fruits Basket.
Both revolve around one ordinary girl being introduced to a group of gorgeous guys, and eventually falling in love with one of them. They are both lovable comedies, as well as moving romantics and if you enjoyed one, I'm sure the other would be a good recommendation.