Sure! Japan is an amazing country with its unique cultural heritage, advanced technology, and beautiful landscapes. Here's what to consider while planning a trip to Hiroshima, Okayama, and Tottori:

Best Time to Visit:
The best times to visit these cities in Japan are Spring (March-May) when cherry blossoms bloom and Fall (September-November) when leaves change colors.

Route and Accessibility:
From Tokyo, you can take a Shinkansen (bullet train) to Hiroshima, which will take approximately 4 hours. From Hiroshima, Okayama is just about 40 minutes away by train, and then from Okayama to Tottori, it's approximately a 2-hour train ride.

Altitude and Acclimatization:
These cities are all at sea level and are in the coastal region, so altitude sickness will not be an issue here.

Accommodation and Booking:
Japan has a range of accommodations from luxury hotels to budget guesthouses. For a unique experience, consider booking a traditional Ryokan. Always make your bookings in advance to avoid any last-minute hassles.

Clothing and Essentials:
Gear up as per the weather. If you're traveling in spring or fall, light jackets or sweaters are recommended. Summers can be hot and humid requiring light clothing and sun protection. In winters, you'll need coats, scarves, gloves, and such. Don't forget to carry an umbrella, as some months can be rainy.

Health and Safety:
Japan is one of the safest countries in the world. Still, remember to carry your personal medication and a copy of prescriptions if any.

Local Etiquette and Respect:
Japanese people are very polite and value manners a lot. When in Japan, it's important to respect local customs - bow when greeting, remove your shoes before entering a traditional Japanese home or a sacred place, and try to learn a few basic phrases in Japanese.

Enjoy your trip to this beautiful region!