Chirashi Zushi (ちらしずし), also known as 散寿司 is the ultimate Japanese party food if you asked me. There is actually no strict rules in preparing this and can be very versatile. All you need is sushi rice and various toppings that you like, may it be raw or cooked. If you want to prepare raw fish, just make sure they are fresh and properly chilled. If you use a nori sheet, you can make them into Maki rolls (卷き) or Gunkan (军舰).
I usually serve this like buffet-style. I will prepare all the toppings and lay them on the table. The guests will just choose what they want on top of the rice. For the above, I prepared the following (clockwise) :
2. Grilled Unagi
3. Shredded Egg Omelette
4. Sakura Denbu
5. Flying Fish Roe
6. Nori Strips
8. Salmon Roe
9. Cucumber Slices
10. Julienned Takuan (pickled radish)
The most time consuming preparation is the prawns and crab, especially the crab. I had to steam then de-shell them. It can be quite tough if you don't have the right tool. There is a type of scissors for crabs but since I don't have it, I used a satay stick to help me. I didn't prepare any raw fish unfortunately; 1) I don't have a sharp sushi knife for cutting fish, 2) old folks don't take raw fish too well. A sharp knife is necessary for cutting raw fish, else it will leave the slices unappetitising and it is a shame to waste good, sashimi quality raw fish.
This is how I make my sushi rice.
Wash rice as per instruction on the package.
Cook 2 cups of rice with dried kelp (5cm length, optional) in rice cooker. Remove kelp after rice is cooked.
Vinegar mixture (This can be adjusted to your taste)
1/4 Cup of sushi vinegar
2-1/2 Tbsp fine sugar
2/3 tsp of salt
1) Stir the vinegar mixture till sugar and salt dissolve. Sprinkle some vinegar mixture onto big mixing bowl (use glass ones, no plastic or metal).
2) Scoop out the hot rice into the bowl. Sprinkle the vinegar mixture on the rice, using a rice scoop to stir well. In another hand, use a fan to fan it (or you can mix the rice in front of the electric fan). Remember not to mash up the rice. When done, cover the rice with a damp cloth.
I much prefer arranging the ingredients using a square container.