Maken-Ki is about an all girls school who become co-ed. In result, our main character, Oyama Takeshi, joins in hopes that he will be able to have an easy school year because of the lack of exams and tests. However, he shortly realises that he bit off more than he can chew since this school is full of highly talanted fighters.
Students at this school use what are called "Maken", which are weapons with unique abilities and powers depending on the compatability with it's user. During a physical exam at the beginning of the series, the teachers there are confused at Oyama Takeshi because they cannot seem to find any "Maken" that is compatable with him. In result, a "Maken" is custom made for him to use.
Now with a "Maken" of his own, he starts a journey to become stronger to protect the ones he cares about. During a battle, he learns that residing in him is a rare power called "Blood Pointer", which absorbs all energy surrounding him to grant him more power. However, he is unable to control it and nearly hurt his friends and teammates.
In an effort to control this power, Oyama Takeshi starts to train seriously both physically and mentally, but will he be able to keep focus with all of the women at his school are trying to make him theirs!?
Overall, Maken-Ki is not original, but is worth a read if you are looking for something new to read with some fighting and haram/ecchi combined. If you are fans of Manga like Historys Strongest Disciple Kenichi, O-Parts Hunter (666 Satan) and/or Love Hina, im sure you enjoy this series.