Hi. New Year's in Japan is quite jampacked especially in well-known shrines. Some of the most popular shrines are the Meiji Shrine, Naritasan Shinsho Temple, Kawasaki Daishi Heigenji Temple, Fushimi Inari Shrine, Atsuta Jingu Shrine, Sumiyoshi Taisha Shrine, Sensoji Temple, Tsurugaoka Hachimangu Shrine, Dazaifu Tenmangu Shrine, and Musashi Ichinomiya Hikawa Shrine.
For temples in Miyagi, you may opt to check these: https://visitmiyagi.com/tags/temples-shrines/
For temples in Yamagata, https://hubjapan.io/articles/4-temples-pilgrimage-shiji-kairo-in-tohoku-iwate-yamagata-miyagi
For temples in Niigata: https://www.japan-experience.com/city-niigata/temples-shrines-in-niigata
And for more information, you may visit this: https://en.japantravel.com/guide/new-years-in-japan/55887