Sunrise is a important for Japanese, if they live in a country of the rising sun.
Especially the sunrise on New Year is the most important.
Japan's longitude is spreading between 153°59′12″ and 122°55′57″. The easternmost point of Japan is Minamitori(Marcus) island, which means you can watch the sunrise at Minamitori earlier than any other place in Japan. However, Minamitori island does not have any permanent residence and it is only open for government personnel. Therefore ordinary Japanese cannot watch the sunrise there.
If you are visiting Japan and want to watch the sunrise, here are the recommended places to watch.
Hokkaido - Nemuro - Cape Nosappu
It is the easternmost point in Hokkaido and in Japan where Japanese and foreign tourists traveling in Japan can visit without any condition. However, it is later than Cape Inubosaki on Honshu island.
Honshu - Choshi Chiba prefecture - Cape Inubosaki
It is not the easternmost point in Honshu but due to the latitude, you can watch the earliest sunrise here on main islands of Japan except the peaks of the mountains.
Honshu - Mt.Fuji
You can watch the sunrise earlier than Cape Inobosaki from the peak but you have to climb up 3776 meters with gears.
Ogasawara(Bonin) islands - Hahajima island
You can watch the sunrise earlier than at Mt.Fuji, but you have to travel more than a day to reach Hahajima island from Tokyo.