Where does the eternal Buddha reside?

From Repaying Debts of Gratitude: 

"The first is the object of worship (honzon). All people in Japan as well as the rest of the world should revere the Lord Buddha Shayamuni revealed in the essential section of the Lotus Sutra as the object of worship (honzon). That is to say, the object worshiped should be the Buddha Shakyamuni and Taho Buddha in the Stupa of Treasures. The other Buddhas standing outside the Stupa and the four bodhisattvas such as Jogyo should be their attendants." 

 In the Kanji Honzon Sho, Nichiren says: 

"Shakyamuni Buddha, the Lord-preacher of this pure land, has never died in the past, nor will He be born in the future. He exists forever throughout the past present and future. 

 and in the Senji Sho, Nichiren says, 

"It was not I, Nichiren, who made these three important predictions. I believe it was solely the spirit of Shakyamuni Buddh who entered my body who made them."

Commentary: The Eternal Buddha resides in our Butsudan, in our hearts, and in our surroundings.