The Tenno is the head of the Nippon Sub-sector. The name Tenno means "Heavenly Sovereign" in ancient tongue as the Tenno governs the Sub-sector in the name of the Immortal Emperor of Mankind. The Tenno's household is sometimes known as the House of Genji but the name is rarely used.
The Tenno's role is the symbolic head-of-state, as if an avatar for the Emperor of Mankind in his absense. When the civilian cabinet wishes to pass the law, they must need the Tenno's blessing to proceed.
The Tenno is also the highest ranking military commander in the region. A Tenno is already either the Grand-Marshall or the High-Admiral when he is enthroned. He can't have the authority to command the other half of the military and someone must lead them in his place.
The role of the Tenno was created by Jimmu. Jimmu was a noble who was given visions to overthrow the warlords and the Shogun that previously governed the Sub-sector, unite all the planets and lead them to prosperity. He lead his army to overthrow the Shogun and established himself as the Tenno, the chosen ruler of the Sub-sector. Shogun Yoshiemon returned during the Horus Heresy to reclaim his power with the help of Chaos. The war tore the Sub-sector asunder and the Tenno emerged the victor. When the Horus Heresy ended, he commenced the reconstruction of the Sub-sector.
Since his death, the title of Tenno was passed on generations to generations, each leaving a significant mark on history. Current Tenno Sugihito is the direct descendant of Tenno Jimmu.
The seal in used on the official flag of the New Empire of Japan. The Imperial Eagle is sometimes placed over the seal to symbolise that it is the Imperial roof Humanity would be under.
A successor must always be male. Usually, it is the firstborn son that takes over the role but there has been cases of younger sons taking the place. If there are only daughters, her fiance will become eligible for the role of the Tenno as he is now "included" to the line of the Tenno. Foreigners are very rare but there has been historical records of foreign Tennos and the most recent foreign Tenno is Donau Macallan IV.
|Time of Reign||Tenno||Notes|
|Various Dates||Unknown (Eventually Seihito)||-|
|956.M41 - 005.M42||Seihito||-|
|005.M42 - 012.M42||Donau Macallan IV||Drookian|
|012.M42 - Present Day||Sugihito||Current Tenno|
It is unsurprising that a number of Tenno had siblings that never became Tenno. Though they are not part of the family anymore they make a minority in the nobility. The following list are those with the Tenno's lineage
- Kiyoe Genji/Macallan
- Jingu Genji
- Alexander Macallan
- Zenio Satsumori