Best Ending:
     For  the  best  ending, give these responses to Mae when you meet
her in the Lost Forest:

Mae: "If I stay here I'll be safe, right?"
You: "Stop!" 

Mae: "Why do you fight?"
You: "For everyone." 

Mae: "Why must you live?"
You: "For finding the answer." 

Get Chris:

Step 1: Talk to the teacher in the room north of the entrance.

Step 2: Search all the rooms on the 2nd floor.

Step 3: Talk to the students in room 2-1. 

Step 4: Go to the casino in Joy Street and talk to everyone there. 

Step 5: Visit the abandoned factory. 

Step 6: Go to Yin & Yan and talk to Chris's mother.
Tell that you know Chris and that you will be his friend. 

Step 7: After leaving the hospital, meet Chris in front of the Sebec Building.

Step 8: Do NOT allow Brad, Ellen, or Alana to travel with you. 

When you meet Chris in Mary's World, he will join you 

Get John:
     First  get Chris then get Juliet and then walk around and you wil
see John standing next to a tree.