Of course! Your journey to Tokyo, Nagano, and Takayama in Japan sounds exciting. Here are some travel tips for a smooth journey:

Best Time to Visit:
Spring (March to May) and Autumn (September to November) are ideal times to visit Japan, offering mild weather and scenic views. However, if you are a winter sports enthusiast, Nagano during winter (December to February) would be perfect due to its famous ski resorts.

Route and Accessibility:
Nagano and Takayama are easily accessible from Tokyo by train. Book a Japan Rail Pass (JR Pass) for unlimited train travel - it's both cost-efficient and convenient.

Altitude and Acclimatization:
Tokyo, Nagano, and Takayama do not have significant altitude variations that would require acclimatization. However, always stay hydrated and take it easy upon arrival.

Accommodation and Booking:
Japan offers a wide array of accommodation options ranging from luxury hotels, traditional Ryokans (Japanese-style inn), and budget-friendly hostels. Booking in advance is always recommended.

Clothing and Essentials:
Pack accordingly to the season you are visiting. For winter, warm clothing is a must, especially for Nagano. If you plan on visiting onsens (hot springs), you might want to bring a personal towel and necessary toiletries.

Health and Safety:
Remember to have travel insurance in case of any emergencies. Make sure to carry any personal medication and keep a note of nearby hospitals.

Local Etiquette and Respect:
Japan has rich cultural heritage and traditions where manners are highly valued. Be polite, respect local customs, try to learn a few basic phrases in Japanese, and most importantly, follow the local etiquette like not tipping, and removing your shoes before entering a home or temple.

Remember to have a Suica or Pasmo card handy for easy access to public transportation in Tokyo. And don't forget to try traditional local food like sushi in Tokyo, soba noodles in Nagano, and Hida beef in Takayama. Enjoy your trip!