You're Mario in this,something happened to mushroom Kingdom and you walking inside it,as you walk in side,everything is cover in green ink,something bad must happened in this kingdom,you walk around for a bit and found peach in middle of a bridge and then Bowser appeared and push the button causing the princess to fall to green ink.

You saw it all,Bowser seems to notice you presence,he push the button to go to you,you took the opportunity to run,but seems like the green ink on the ground slow you down,Bowser almost catch up,seemed amused by your futile action.

Ink bowser: “mario~! You know is impossible to get out of here? Come and join me and we SHALL RULE THE KINGDOM~! come on darling,just one time,it doesn't hurt to try,isn't it~?” he said in deep voice,he then chuckled at your stubbornness to not join him you almost out of the castle! You can do it! The door is in front of your sight now!