For anyone who does not follow trends, Manga is a type of Japanese graphic novel. Its so popular here that the library has several popular issues on the shelves they regularly check out.
I found several math books in Manga style for a variety of grades. Learner Books publishes several Manga style books for grades 3 to 5. The books cover probability, fractions, geometry, multiplication and division, money, distance and measurement, and time and temperature.
Although they are not for high school aged students, I have a few students who have missed certain basic skills and might need scaffolding. They books might be the right reading level for many of these students and they might help them catch up. Nothing wrong with providing interesting material.
For high school, there is a series of books from No Starch Press called the Manga guide to _____________. There are editions for statistics, calculus, linear algebra, regression analysis, or tons of science topics. Each is drawn in the manga style with a story designed to teach people about the mathematical topic. For instance in the linear algebra book a guy is exchanging teaching a girl linear algebra in exchange for martial arts lessons from the girl's brother. There is a love line but the math is solidly embedded in the book. The books all have good reviews on Amazon.
I'm revisiting Manga High because they now claim they work on tablets but when I tried the games on my iPads, a adobe flash needed page popped up and so I couldn't go any further. I tried it on a Computer and it works well on the computer. I tried the wrecks factor game, easiest level and it was both fun and challenging.
The idea behind the game is that a trinomial ship wrecks and you have to cover an area of the grid so the trinomial is factored. Say you have x^2 + 3x + 2 is factored into x + 1 and x+ 2. The x is the corner so you go up one block and over 2 so the whole area is in green. If you are right, the helicopter flies in to rescue the people.
In addition, as a teacher, you can set up classes to assign games, quizzes, etc and the site keeps track of the their results. The results give you all types of information so you can see how they are doing, what they need to work on and other information. As I said earlier it does not work on my iPad but I do not have the latest up to date OS on it and I have to check on the adobe aspect. The site does say it will work so I'm going to investigate that. I'll keep you posted as I figure this out.