First off, I do really like the basic premise and the suggested bits for building out the PC's relationship with the deceased friend. The overall flow is clear (once I read your comment below at least),the mystery is engaging, and your use of the "Love 2.0" theme is top-notch.
On a personal note, this system (and the very concept of a solo mystery game), is new to me, and idk if i like it. In a mystery, I wanna find out what happened, not make something up and then roll dice to see if it is retroactively the correct answer, but I get that that is how this game is played, and not all games are for all players. This is probably a gripe I have with HARDCASE though, rather than your mission itself, but I can't be sure, having not read HARDCASE or TRUTHSEEKER yet.