What have we here? The story of your neighbourhood shota. Kou-chan is the 13 year old schoolboy all the best-looking girls want. But it's Natsuki, the four years older beauty that we care about the most.
Ane Doki! is quite predictable. Most of the cliches of the genre you can think of, are there. Kouta, our protagonist, is a pre-teen who's completely clueless when it comes to his feelings, as well as those of others. Natsuki, our sexy female lead, randomly decides to devote her life to serving this kid. The convenient absence of parents? It's here, times two. The occasional clumsiness that leads to erotic sights can't be missing. And since there's a girl moving in to a boy's house, of course another girl will decide to move in, to "keep an eye on them". Check.
The twist here is supposed to be the age gap between the two; a point of interest should be the moment Kouta's cute classmate starts having feelings for him. Thing is, the dilemma "sexy versus cute" is actually non-existent. The role of alternative love interests is demoted to people that exist merely to help Kouta realise he's fallen for the older hottie.
The characters are visually attractive and nicely drawn. We get a whole lot of fanservice like girls in their underwear or accidental groping, but nothing too extreme. In fact, there is but a single kiss throughout this manga. While Kouta's feelings for Natsuki do delevop, and we get some interesting insight on his thoughts and expectations, Natsuki remains the girl who happily helps and praises him the whole time, something rather shallow.
With only 26 chapters, Ane Doki! remains interesting. That is, if you want to live out the honorable fantasy of the boy who aims for the older, ridiculously hot girl.