Akihito (明仁) is the current Emperor of Japan since 1989.
He's just an Emperor now. He rules Japan.
He just won awards, made appearance on TV at one point, mind.
He did visit the region of Nepal (located in Kanako's India) once, in 2001.
In the past, he just watched and learned about science and technology as well.
Upon him gain Emperor status, he requested that the Prime Minister cosplaying Koishi Komeiji (Takako Kawasaki) changed the Empire of Gensokyo to Nippon-koku. Takako Kawasaki did that, and so Nippon-koku was the official name now.
He visited Korea for a StarCraft tournament once in 2004, and came in 4th place.
After the real Koishi Komeiji came to Japan in 2011, she was elected as Prime Minister almost immediately upon arrival. Akihito had met Koishi as well.
In fact, when Akihito and Michiko dies, Akihito has said that Koishi will be able to have a Semi-Empress status along with being Prime Minister. Sayako Kuroda is to really succeed Akihito upon death.