After rewatching this, I doubt that Otani was being forced by Risa's friends. I highly think that Otani was slowly self-realizing his emotions, way back to his middle school Christmas party event. This is not about pressuring to like her, but they are encouraging him to be more honest with his feelings. And that ending with him blurting it out from built-up frustration and jealousy was a major upset. Otani, aho!