If you liked the Kodomo no Jikan (2007) anime, the Anime-Planet community thinks you'd like:
Asami Onohara is a typical seventeen-year-old high school girl – except for the fact that she’s married to her physics teacher, Kyousuke Ichimaru. Since a relationship between a teacher and student is inappropriate, the two must hide their status from the world; in fact, the two have not yet consummated their marriage. As their everyday lives continue, new obstacles to their love present themselves daily. Can the two keep their secret safe, and will Kyousuke ever show his affection for Asami?
Kodomo and Okusama deal with a student/teacher relationship in both a comical and serious way. Although Kodomo is more of a one-sided love, it shares the same theme and dwells into the heart of a young girl who wishes for a more romantic relationship with her teacher.
In the present, the Japanese government has been conducting experiments to genetically engineer a human: a girl named Rizel. The experiment was a success -- sort of. While healthy and cheerful, 12-year-old Rizel also ended up possessing the uncanny need for “love” to further her development, as well as tears which were in fact volitile explosives! When sadness can end up destroying a city block, what's a girl to do except... get married?! For Iwari Tomori, the young man chosen as the most appropriate partner for Rizel, life is about to change, for better or for worse!
Both of these anime involve a little girl that is in love with a boy/man that is older than themself. I watched Kodomo no Jikan way before I had ever watched Rizelmine, but watching Rizel I kept thinking of KnJ. I also enjoyed both a lot, so if you enjoy one of these series, chances are you'll like the other just as much.
When Makoto saw Kotonoha on the train one day, he fell in love at first sight. Luckily, his classmate Sekai’s nosy personality ensures him an introduction to his crush, and soon the two begin to date. However, Kotonoha isn’t the only one with eyes for Makoto - a fact that any horny teenager would be delighted with. With endless temptations, lies and heartbreak at every turn, Makoto and Kotonoha’s relationship will soon be put to the ultimate test...
Both anime deal with inappropriate 'romantic' situations and bizzar love triangles. However, KnJ is very, very loli, and that might disturb some people. If you want an uncomfortable 'romance' but with a more comfortable age-range, you might like School Days
At St. Mihailov Academy, strange things are happening. Not only did the dean disappear, leaving his daughter Tomo and adopted daughter Mafuyu alone, but girls in the nearby city are being killed by an unknown foe. However, the blades begin to fly when a Russian boy named Sasha arrives. He is a Qwaser, a person able to manipulate the elements after ingesting Soma, breast milk, and he’s not the only one. Soon Tomo and Mafuyu find themselves in the middle of a battle between two groups of Qwasers whose goal is to protect or steal the Theotokos of Tsarytsin. With more allies and enemies arriving, who will survive the assault?
Both of these anime are extremely perverted; especially the loli characters. Also, you have to make sure you watch both of these uncensored, as they are both so incredibly chopped up and editted that you just cannot take it seriously while watching it censored.
Rito Yuki is a bumbling boy who wants nothing more than to confess his love to the lovely Haruna, but a variety of obstacles always seems to stand in his way. One day, while relaxing in his bathtub Rito found his hands full - literally - with the breasts of a strange alien girl named Lala who suddenly appeared in his lap! She is the princess of Planet Deviluke, and she has run away from home to escape the prospect of an arranged marriage; and unfortunately for Rito, his accidental groping is the traditional engagement ritual of his otherworldly guest! Deviluke's emperor will destroy Earth if Rito backs down from his "proposal," but all he really wants to do is be with Saruyama! Naked antics, magical powers, misunderstandings, Lala's marriage-happy family and Rito's own shyness are many of the barriers he must face in his attempt to win the real love of his life – that is, if Lala doesn't win him over first!
Even though both are set in a different time (one being in highschool and the other in grade school) both have many similar aspects. Like, how both the male lead character have to deal with the mischievous female lead character. Also, how both female lead character initially loved the male lead character, but decided to slowly progress at the end. So if you like watching one of them you should try watching the other