For the Deviled Eggs:
In a bowl, thoroughly combine the egg yolks and mayonnaise. Fold in mentaiko. Add equal parts Dijon mustard and sesame oil. Mix to combine, spoon mixture into a piping bag, and pipe into egg white halves.
For the Blood Orange Gelatin:
In a saucepan, bloom gelatin with ½ cup blood orange juice for 5 minutes. Heat the gelatin mixture until simmering and gently stir in the remaining blood orange juice. Pour mixture onto a plastic-lined sheet tray and set in refrigerator. Using a ½-inch ring mold, cut gelatin into discs.
To Assemble and Serve:
Top each Mentaiko Egg with one Blood Orange Gelatin disc. Garnish with chives and togarashi.