Difference between a main and supporting character

Jakerams said:
I understand that but I am talking about myanimelist guidelines because for example Tachibana Marika should be labeled as a main character yet she's stuck in the supporting character role in this database.

ReaperX- said:
Tachibana may have had some arcs, and may be one of the chosen girls, but I still would not label her as 'main' character. In truth, the only 'main' characters are Chitoge, Ichijou and Onodera..

Jakerams said:
Marika easily plays a bigger role in the story than Chitoge and Kosaki. Kosaki has nothing going for her in the story minus being a love interest of Raku's meanwhile Chitoge character has developed overtime but she has done nothing storywise. Meanwhile Marika character developed overtime, she also influence the protagonist to the point the story changes for the better, she is still one of the potential 4 promised girls (even though so is Yui but she wasn't used except to spark the development of Raku, Marika, and Chitoge.) so Marika plays a very important role in the story. A main role considering the story isn't just Kosaki and Chitoge. Another example would be that Yui had only a few chapters before she got her reply from Raku meanwhile Raku said what he was going to do but he never got the chance to because a huge story arc developed in which no side character in Nisekoi would ever get.