Girl just tell him the truth how is he suppose to expect to guess you're the girl from tha...

Yeah well, if someone turned up to you and told you that they're someone they knew when you were a child who died would you believe them? You wouldnt, rather you'd probably be angry and disgusted that someone would tell you such a lie, and espescially in his case where hes the son of the chairman and people know about his friends death from childhood he would assume it's a ploy to get close to him by pretending to be his dead friend. The best and pretty much the only way to do this is try and get him to remember her and realise it's her by getting to know him slowly.