You can't save Tomoko at all and to save Curly you need to get in the one room in the water way once you use the tow rope on her and if you go back to the guy and give him the polar star you get the spur, its level 1 attack is the polar stars level 3 and if you charge it by holding it you get a laser that goes through targets and does tons of damage. Sorry if you already found this out or something.