You are walking around your friend, James house to be exact. And when you see a disk on the floor you pick it up and are knocked out. When you wake up and see Chara you get confused. But when you see someone else behind them, taller than Chara, you realise you're in an Undertale game and that these 2 weren't the original's.

Kara.EXE: "Hey there, names Kara. You are? and why mess with MY love James?" She says pointing at you, She and her puppet, Chara.