Shadow and Sonic meet again after 15 years of everyone separating after Eggmans death. What happened that got everyone to separate?

Hi, I'm Sonic the hedgehog! I'm a Jr in high school and I've sorta got a problem with a senior... (well more like he has a problem with me) But things are getting a little weird... at once i was trying to avoid him as much as i can, but now he's all I'm thinking about lately... I just want to understand him, maybe he'll stop hitting me! As always thank's for reading and don't forget to vote and or comment! <3

After being mysteriously taken, Sonic is forced to join G.U.N. Tower claiming Sonic is now G.U.N property after his secret is uncovered. Shadow now has an unwanted parter, though is seems Sonic isn't happy with his new team either. When they both realize Sonic wants a way out of G.U.N Shadow decided he will help, only to get Sonic off his team. But why is it so difficult to get Sonic fired? Why won't Tower set him free? Sonadow

Shadow and Sonic are assigned a very dangerous mission with Rouge and Omega. This isn't a problem for Rouge or Omega, but the two hedgehogs aren't so happy about it, since they both secretly have feelings for one another. No one knows about Shadow's feelings and no one knows about Sonic's. The problem? Homosexuality is illegal. (Ps. It's nothing like the movie "Mission Impossible")

After Sonic is killed in battle against Black Doom, his friends return him to his birth place; Christmas Island, where the Queen revives him. Upon doing so Shadow asks the Queen to rid every memory that Sonic ever had of him in order to protect him from what he thinks is a deathly curse he has. (As anyone he loves and holds dear seem to die) While fighting Eggman and his awakened Demi god, Shadow is injured and knocked unconsious. The only one to help him now is a blue hedgheog who can't help but admire him and think, 'Do I know you?' Can Shadow keep Sonic from not knowing him, let alone falling back in love!?