This goes over the steps to complete each of the 5 characters but doesn't have any real gameplay advice.

Rusty

1. Duel Marcus at the Restaurant
2. Duel Ice Cream in the Mall
3. Duel Fire Monk in the Junkyard
4. Duel Greg at the Restaurant
5. Duel Sera at the Mall
6. Duel Marcus at School
7. Duel Lucy at the Restaurant
8. Talk to Trey in the park
9. Duel NPC in junkyard
10. Duel Knight in the Junkyard
11. Duel Earl in the Junkyard
12. Duel to Downey in the park
13. Talk to Marcus at the Card Shop
14. Duel Trey at the Mall
15. Duel Caitlan at the Restaurant twice
16. Duel 2 NPCs in Junkyard
17. Duel Fire Monk in Junkyard
18. Duel Norskyler
19. Duel Knight in the Tournament Hall.

Luc

1. Talk to Mr. Lynn at School
2. Duel Geoff (automatic)
3. Duel Simon (automatic)
4. Duel Caitlan (automatic)
5. Duel Hot Rod at the Restaurant
6. Talk to Rebecca at the Mall
7. Duel Robin in the Card Shop
8. Duel Suzanne in the Power Plant as soon as you enter
9. Duel Knight in the school
10. Duel Karl in the Mall
11. Duel Jodi in the card shop
12. Duel Mikey in the Restaurant
13. Duel Sera in the Power Plant
14. Talk to Marcus in the card shop
15. Duel Knight in the School
16. Talk to Corona at the Power Plant
17. Duel Ernie in the Park
18. Duel Geoff in the Card Shop
19. Duel Abagail in the Mall
20. Duel Ms. Loodle at the school
21. Duel Earl in Tournament Hall
22. Duel the Light Monk at the Power Plant.
23. Duel Illium (automatic)
24. Talk to Knight in the Tournament Hall.

Flynn

1. Duel Caitlan in the Tournament Hall
2. Duel Savy at the Mall
3. Duel Darkness Monk at the Museum
4. Talk to Dust in the Museum
5. Duel Sera at the School
6. Talk to Dust in the Museum
7. Talk to Source in the Park
8. Duel Colin in the Library
9. Duel Pete in the School
10. Talk to Markus in the Mall
11. Duel Evan in the Card Shop
12. Duel Knight in the Museum
13. Talk to Source in the School
14. Duel Greg in the Card Shop,
15. Duel Anastasia in the Park,
16. Duel Greg in the School,
17. Duel Gwinny in the Mall,
18. Duel Oliver in the Tournament Hall
19. Talk to Earl in the Tournament Hall
20. Duel Savy in the Museum,
21. Duel Lynne in the School,
22. Sell cards then Duel Chuck at the Card Shop (costs 20 cerdits)
23. Talk to Source in the Park
24. Duel Earl in the Tournament Hall
25. Talk to the Darkness Monk in the Museum
26. Duel Phlael
27. Talk to Knight in the Tournament Hall.

Rebbeca

1. Duel Luc (automatic)
2. Duel Cindy in the Library.
3. Duel the Water Monk at the Mall
4. Duel Widow in the Park
5. Duel NPC in Library
6. Duel Ms. Loodle in the Library
7. Talk to Jodi in the Park, Duel Sera
8. Duel Evan in the School
9. Talk to Chuck at Card Shop, Duel Hooper
10. Duel Evan (automatic)
11. Duel Sean (automatic)
12. Duel Knight in the Restaurant
13. Duel Duncan in the Card Shop
14. Talk to Luc in the Park
15. Talk to Cindy in the Library
16. Duel Drew in the Restaurant
17. Talk to Widow in the Park
18. Duel Jalen at the school
19. Duel Water Monk at the Library
20. Duel Ambergris (automatic),
21. Talk to Knight in the Tournament Hall.

Trey

1. Duel Finch in the School
2. Duel Marcus in the Park, (Knight interrupts)
3. Duel Nature Monk in the Forest Preserve
4. Talk to Rebecca in the School
5. Duel Earl in the Card Shop
6. In any order; Duel Johannes in the Tournament Hall (3 shields) Take Xeno Mantis out of your deck, Duel Eric in the Restaurant (No Double Breakers) Duel Hot Rod in the Mall (no evo)
7. Talk to Chuck in the Card Shop.
8. Duel Jalen at the School
9. Duel Sera (automatic),
10. Talk to Marcus in the Park
11. Duel Knight in the Forest Preserve
12. Duel Earl at the Mall
13. Duel NPCs until master rank (Normally 5 games for me)
14. Duel the Nature Monk in the Forest Preserve
15. Talk to Gor (automatic)
16. Duel Marcus in the Park
17. Talk to Nature Monk in the Forest Preserve
18. Duel Gor (automatic)
19. Talk to Knight in the tournament Hall.