So..... Reading the Love Stage Manga.... I can guess that Ryouma, before he had sex with Izumi, was in love with the girl Izumi right? So does that mean that there's a high chance that Ryouma used to be a virgin before they did it? Because Ryouma doesn't look like someone who would have sex with any girl.... Or am I not right?

Probably. Considering how much effort he put into trying to find Izumi, he likely only had eyes for "her" the whole time.

probably?? Oh my, but I can't see Ryouma as someone who would fool around with girls.... Huwaaah >< He must be a virgin before ><