Sekai Ichi Hatsukoi: The World's Greatest First Love (2011)

Three couples, three intense romances: a student’s tutor crosses the line, a loner meets a force of nature, and a carefree man faces love he can’t ignore.

Shion and Rui are the dream team when it comes to hitting on women. Tonight was going to be another night of hooking up with girls for Shion, but he ended up taking a strange drug. When he woke up... he'd turned into a girl?! Rui came looking for Shion, but didn't recognize him, and started hitting on him...

The story follows Rena Yukuhasahi, a reserved office lady and Ryouhei Hachiya, a businessman and fellow colleague. Yukuhasahi appears to be the most reserved girl in the company, but becomes a super beautiful woman when she dresses up. Flustered in the presence of her transformed self, Hachiya insists on taking her out, only to find themselves in front of a love hotel.

Kinoshita Kazuya is a 20-year-old failure of a college student. He managed to kiss his girlfriend once, but was dumped after a month. Completely spiteful, Kazuya uses a certain method to date a girl. He goes to their meeting place and a beautiful girl brushing her long, black hair behind her ear was there, smiling at him. Her name was Mizuhara Chizuru. Something real is born after just a single rental! A reckless rom-com filled with love and excitement is about to begin!

Kaoru is a college boy with everything going for him. He lives in a mansion with his beautiful fiancé, Aoi, all his roommates are babes, and they all have the hots for him. There’s just one hitch: due to family complications, Kaoru and his beloved have to keep their engagement a secret. As he gets tangled in countless steamy situations, can Kaoru overcome temptation and stay true to the lovely Aoi?

Shinichi Sakurai’s one wish is for a little peace and quiet. But Hana Uzaki — his boisterous, well-endowed underclassman — has other plans. All she wants is to hang out and poke fun at him. With the help of her chipper charm and peppy persistence, this might just be the start of a beautiful relationship!

When bashful Miyano meets brash Sasaki, it feels like a teen romance manga come to life — but for these boys, real-world love is messier than fiction.

"A girl in a lower grade just made me cry!" One day, Senpai visits the library after school and becomes the target of a super sadistic junior! The name of the girl who teases, torments, and tantalizes Senpai is "Nagatoro!" She's annoying yet adorable. It's painful, but you still want to be by her side. This is a story about an extremely sadistic and temperamental girl and you'll feel something awaken inside of you.

16-year-old super-studier Nagi Umino, second-year student at the Megurogawa Academy high school, was switched at birth. On his way to a dinner to meet his birth parents, he accidentally meets the brash, outspoken, Erika Amano, who is determined to make Nagi her fake boyfriend as she never wants to actually marry. But once Nagi makes it to dinner, he finds his parents have decided to resolve the hospital switch by conveniently having him marry the daughter his birth parents raised...who turns out to be none other than Erika herself!

Tamahiko Shima has been exiled to the country because of his disability, but the sudden arrival of an arranged bride upends his lonely life.

Socially awkward Aharen-san has personal boundary issues, either getting too close or too far from her classmates. When fellow student Raido picks up an eraser she drops, Aharen-san decides they’re now best friends. Whether studying, playing the arcade, or just eating lunch—she’s along for the ride. What follows is an impromptu bonding that shows affection can blossom in the unlikeliest of places!

Down-on-his-luck Koushi Nagumo wanders the streets unemployed, homeless and in search of his next meal. His fortunes improve after a chance meeting with a vivacious young woman whose proposition seemingly solves nearly all his problems. Thanks to her, Koushi enters the welcoming halls of a dormitory at a women’s college… only this particular assignment is no stuffy, sleepy affair. The Goddess’ Dormitory is known for housing the college’s most unruly students! If he wants to keep a roof over his head, Koushi must become the “Dormitory Mother” charged with maintaining order and good discipline. But doing his job and keeping his sanity are no small feat with characters as endearingly eccentric and untamable as these!

While spending summer with his mother, Haru meets Ren, a boy newly adopted by his mother. Getting along with Ren isn't easy as Haru's goal is to "civilize" him by the time summer ends. Their relationship slowly improves as Haru spends more time with Ren and in return Ren steadily warms up to him. Can they really become a "family" at the end of summer?!

Naoto Watari lives solely for his little sister, Suzushiro, until his chaotic childhood friend, Satsuki, storms back into his life. Without uttering a single word, her very presence ignites buried memories and unravels his rigid routine. As tensions rise and secrets surface, Naoto’s devotion to Suzushiro clashes with unresolved pain, threatening to collapse his fragile world.

First-year Toono transfers from Tokyo to the all-boys boarding school deep in the mountains, "Mori Moori Private School." The friendly Yaguchi who calls out to him becomes his only friend, but his dislike of sports makes him join the most laid-back looking photography club instead of Yaguchi's soccer club. However, the photography club is in name only and is actually nicknamed the "Yarichin Bitch Club," filled with colorful seniors. In contrast to the troubled Toono, Kajima, who joined the club at the same time, is completely unphased and even slips a confession to Toono into the confusion. Toono himself thinks Yaguchi is cute, but Yaguchi finds himself blushing around Kajima and stuff happens. Furthermore, complications arise between the seniors…

Asahi Kashiwagi lives the typical life of an average high school student — until the day a TV fortune teller’s predictions come true one after another, culminating in a series of risqué encounters! Destiny seemingly draws five beautiful girls into Asahi’s path, and soon he finds himself fielding not one, not two, but five love confessions. Asahi will need to follow his heart to find the perfect love for him, or else his love fortunes may end in one epic flail and flop.

The anime follows a salaryman who has a chance meeting with a girl named Ai on the train. They begin to meet every Monday on the train, with the man serving as her bodyguard on the crowded commute while they chat.

The story centers on third-year high school student Jiro Yakuin, who gets saddled with his gyaru classmate Akari Watanabe for the class's "marriage training" project about practicing to be a married couple. Jiro is the complete opposite of Akari, but the two know that if they do well they will be able to switch partners to end up with their respective crushes, and so they force themselves to act like the perfect married couple.