Astarotte no Omocha!

*Both girls are what you call tsundere I guess. *I am more into mature woman/girls but in these both anime girls are the ones that never grow old I hope you know what I mean ;D * Magical world theme and into that world a human is put and than the story begins. * Well if you watched Zero long ago or maybe even recently than you can check this airing series out ;D 

A boy from the human world comes to another world because a girl(both voiced by Kugimiya Rie and are lolis) needs him for a reason: as a familiar for Zero no Tsukaima and as part of a harem for Astarotte no Omcha! The worlds the boys are summoned to use magic and have magical creatures that only exist in tales. And notably, both series are ecchi, although not very.  

An ordinary guy falls into alternative world which is based on magic principles. Our protagonist becomes a servant of loli tsundere ojousama heroine so in both anime we will see the same pattern of relationships. Either Louise or Astarotte are voiced by Kugimiya Rie who is well known for voicing the most famous tsundere characters. Both anime have a lot of ecchi and it's on the first place in AO but ZT also have an interesting plot (at least the first season of ZT). There is also maid heroine (Effie -- Siesta). And Ini will remind you of Tabitha (kuudere type). 

both are about someone transported to another world 

there similar because of a boy being sent to another world with magic. it has some comedy, and romance, and a little bit of action 

Both anime have the male protagonist summoned to another world to help a royal girl to grow up. Both end up them separating near end of anime but they still get together at the end and all is good and nice. Both of them have lots of commedy moments and are worth watching. 

If you like tsundere girls and the main character being teleported into another world this fantasy anime is for you. both have some fanservice. Both girls don't like their new male friend at the beginning but that changes them slowly into tsundere girls.  

Watching the first two episodes is enough to notice some similarities between Astarotte no Omocha! and Hayate no Gotoku! First physically, both (Nagi and Astarotte) are small-sized, blonde haired and green-eyed. After this, behaviors, both are a little bit selfish and distant at the start (Tsundere in other word). You'll also notice that both feel lonely in their vast realm (mansion in Nagi's case). To conclude on girls, both have Rie Kugimiya for voice actress. Hayate and Naoya are especially similar in behavior, they'll do anything to satisfy their little master, to summarize they are totally devoted. They are both involved in a world that they don't know. Hayate no Gotoku! is more focused on humor and anime/manga references. read more 

As original manga reader, Astarotte is very similar to Hayate the Combat Butler, both have a ojou-sama and a servant, the relationship is pretty much the same moreover with the tons of ridiculous and crazy secondary characters that will appear in the next episodes. 

In both series there is little girl and her "babysitter". Mains char voice, Lotte, is the same as Nagi. Both are fine, and somehow funny series with a little bit of romance. 

Astarotte no Omocha! and Hayate no Gotoku! have many same things. First of all, the setting is pretty much the same: a blonde, rich-tsundere girl encounters with blue-haired guy/boy, who becomes her butler. Both shows also follow the relationship between the butler and the girl, giving also hints of romance between them. Also, the main girl is voiced by Rie Kugimiya, and the butler is voiced by girl in both series. However, there are also couple of different things: while Astarotte has more fanservice (ecchi) plus colorful and bright animation, Hayate concentrates more on school-life, and doesn't have that bright animation (expect in the second season). Although, Hayate also has parodies really many shows while Astarotte doesn't do parody of anything. The comedy is also pretty much different. read more 

The butler is often dragged around and bullied by his mistress who is a blond, child and a tsundere who loves her butler more than she cares to let on.  

A boy from human world comes to a world of mysterious creatures and fantasy theme, and they got the princess, though the both have Ecchi and romance. 

Looking for something funny or cute? Then, these two series may be for you. Let's see why: - both series contains comedy - both involves being summoned to another world involving the supernatural - similar conflicts - both contain light romance - both are also somewhat heart-warming - both contain a little ecchi You get the idea. 

In both shows there's a boy who gets transported into a fantasy world with lots of cute girls. Another similarities are that there are elf-like people, magic, maids and a loli princess who seems to develop some romantic feelings for the MC. 

They both revolve around an older guy being brought to a younger Princess in a medieval fantasy-like world. Astarotte no Omocha has a better plot and, in my opinion, is the better of these two though. 

They're both loli shows that are surprisingly decent by being somewhat heartwarming. 

Both have adults(teenager in PnIwK) taking care of kids, both are ecchi, and a harem if you think about it. 

Both anime have the same CVs whom is Rie Kugumiya Both of the characters are tsunderes Both characters make their male friends as servants. In Toradora, Taiga make Ryuji as her dog and in Astarotte, Astarotte Ygvar make Naoya Touhara as her 'toy' 

Both centre around a story of demons. It is also rumored that Astarotte will make an appearance in Disgaea 4. Making her an honorary Disgaea demon. Though ironically, for the synopsis of this show, other than the sexual rapey stuff, which is mostly only implied and lightly hinted at for most of the show, the Astarotte demons are on the whole, much more 'normal' and more ethical than the Disgaea demons, showing a much greater tendency towards kindness and human morals instead of backstabbing, than Disgaea. Still, each of these might be appealing to you if you like one. 

If you like cute anime with lolis like kodomo no jikan i recommend astarotte no omocha