The arms of the Imperial House of Nishi
| Style | His/Her/Their Majesty |
| First Holder | |
| Current Holder | |
| Heir | |
| Residence | Hall of One Thousand Chrysanthemums, Nishima |
| Appointer | Nomination by incumbent, limited to blood relations (de jure) Hereditary, absolute primogeniture (de facto) |
The Emperor of Aika, or Tennō (aikalanguage for "Ruler of Heaven" or "Heavenly Sovereign"), is the head of state of Aika. The Emperor is officially an absolute monarchy, though the power of the Emperor has waxed and waned over the course of Aika history, with periods of Imperial supremacy and periods of either shogunate rule, clan rule, or de facto anarchy. At present, the Emperor is a mostly symbolic tradition under the rule of the Takeya Shogunate.
Since the foundation of Aika in fourth century of the Fourth Age, the position of Emperor has been held by the House of Nishi.
Emperors of Aika
- Kawahito the Unifier, the first Emperor
- Sogohito, Kawahito's son and successor
- Uehito
- Tarohito, married Saisho the Great and helped introduce samurai culture to Aika
- Suihito, known as the "Samurai Emperor," daughter of Tarohito and Saisho the Great, trained in samurai ways and bushido
- Johito, Suihito's daughter and successor
- Rusuhito
- Hikihito, the current Emperor