Boil water in a small pot. Drop a few drops of sake and cook chicken until done. Shred the chicken and let it cool.
Remove tofu from the package, drain. Cut it into bite sized pieces.
Cut the cucumber into small cubes, and chop the scallions.
In a small bowl, mix shredded chicken, cucumber, scallions, and the dressing together.
On a plate, place tofu and pour chicken mixture on top.
Garnish with arugula and enjoy!