In the world, there are those who hunt down rare and powerful items known as Lost Precious, including Ryuuji Kisaragi’s own parents and cousin Erika, who’s been studying abroad for the last few years. But when Erika suddenly returns, the boy finds himself in the middle of the action when she drags him along to intercept a special treasure from the nefarious Fang organization. What’s more, the duo soon discovers that this Lost Precious isn’t a jewel or trinket, it’s a rare dragon girl who instantly bonds with Ryuuji! Now, Ryuuji and Erika must help teach this dragon - who they name Rose - about the world, while keeping her safe and meeting other new friends and dragons along the way.
I can't quite put my finger on why I feel these two are so similar - both involve a fantasy-type of girl (dragon or vampire) and her somewhat ecchi relationship with a guy, both plots meander all over the place and imo seem quite generic/uninteresting. Call it a gut feeling, I think fans of one would probably like the other.
Makoto Niwa has just moved from his rural hometown to live with his aunt and experience high school life in the big city first hand. Unfortunately, his dreams of an adolescence filled of dates and school activities are soon shattered by having to share his new home with Erio, his deluded cousin who thinks she's an alien and spends most of her time wrapped in a futon for protection! Now, in addition to enduring his aunt’s energetic attention and flirting awkwardly with the girls in his class, Makoto finds himself drawn into helping Erio rejoin regular society and stopping her 'alien' antics.
Dragon Crisis! and Denpa Onna to Seishun Otoko both revolve around the idea of an eccentric girl. They are both more character based than plot based, although they have a decent amount of plot as well.
Akuto Sai enters the Constant Academy for Magick Arts hoping to become a high priest and change the world for the better. But when the school's oracle declares his future profession to be 'Demon Lord', he finds himself feared and hated by the entire student population. Now, instead of making comrades and studying for his exam, Akuto finds himself fighting off monsters, bullies, and well-meaning classmates in various states of undress. If navigating a magical high school as a transfer student wasn't difficult enough, Akuto now has to deal with a cute android ordered to observe him 24-hours a day, the precocious attention of the flying, invisible and naked Keena Soga and the advances of the school's most popular girl. Will he be able to overcome his fate, pass his classes, and mend his friendship with the violent Junko Hattori, or will he succumb to his demonic destiny?
Okay so besides the fact that Ichiban has a lot more ecchi than Dragon Crisis could even hope to have as well as the fact that a majority of Ichiban takes place in a school setting. Both series do have quite a few similarities. For example most of the main characters have some sort of special abilities whether that be that they have magical powers, are dragons, or whatever else. Also the battles to me at least had a very similar feel to each other. While there are several differences between the two each series has enough in common that if you liked one then you may find yourself liking the other as well, but at the same time they have enough differences that each is a somewhat new experience.
To make money, high school student Shinkurou Kurenai works for the secretive Benika as a "dispute mediator," acting to intervene in the disputes of clients – often violently. One day, Benika gives him a much different assignment: to protect Murasaki Kuhoin, a seven-year-old girl from the wealthy Kuhoin family. This turns out to be a more troublesome task than he expects, as Murasaki is spoiled, naive, and completely unaware of what life is like outside of the luxurious one she had previously. He also has no idea why Murasaki needs his protection, though he is slowly obtaining details from a well-informed classmate. Adding to his problems, Shinkurou still must continue to do his previous work for Benika and take care of his social relationships in school while protecting Murasaki, complicating his entire life. Nonetheless, as time passes, he and Murasaki grow close; however, trouble brews in the shadows as everyone - including Shinkurou - seems to be harboring secrets...
Lotte, the princess of Ygvarland, hates men - a fact that ordinarily wouldn't be a problem given she's just a child. There's just one issue: the girl is a succubus that must suck the life seed from the male species or die! Now approaching adulthood, Lotte must learn to tolerate the opposite sex, but her royal highness won't have any of it. That is, until Judith, the girl's lady-in-waiting, brings Lotte a human boy to the demon world. This unfortunate young man, Naoya, must now open the princess's heart to his gender, but as caring and considerate as he may be, he'll certainly have his work cut out for him!
Blonde supernatural lolis that are taken care of by nice caring young man, add oddles of fanservice and pantyshots: if you find the premise enjoyable then you will like these anime. Lotte no Omocha is what it is, with a questionable premise that will make many cringe; Dragon Crisis adds a action and an harem angle to the plot.