Historic temple and bustling Nakamise shopping street offering inexpensive souvenirs and street snacks; great introduction to Tokyo. Senso-ji area is typically open from early morning through evening (temple grounds free).
Walk Ueno Park (free) and pick one affordable museum (Tokyo National Museum or National Science Museum) if interested — check museum hours (usually 9:30–17:00).
Bus to Yudanaka then 30–40 min walk to the park to see wild macaques bathing in hot springs; park generally accessible 8:30–17:00 — plan for cold, snowy conditions and a moderate walk.