Combine the marinade ingredients in a large bowl. Add the beef tenderloin pieces and massage to coat. Chill the beef in the marinade for several hours, up to overnight.
When ready to cook, heat the grill to medium high. Skewer the beef pieces onto metal skewers, about 6 beef piece per skewer. Grill the skewers directly over medium heat for 2 minutes per side. Serve the skewers over rice. Mochi dessert optional but highly recommended!