Solo Travel to East Hokkaido. Looking for some advice on itinerary

Hello! I will be visiting East Hokkaido on a solo travel around late June. My brief itinerary outline as per below. Is this itinerary too packed or is it fine? Any other places I should be visiting that was not listed? Any advice would be greatly appreciated. Thank you!

Day 1

Arrive Kushiro Airport at 9.25am

Drive to Lake Akan (reach approx. 11am)

Check in New Akan Hotel, Lunch (11am – 2pm)

Lake Akan

Mud Pools (2pm – 3pm)

Lake Akan Cruise – Churui Island

Marimo Observation Centre (3pm -5pm)

Akan Ainu Kotan (5pm – 7pm)

Day 2

Brunch (10am – 11am)

Lake Onneto (11am – 12pm)

Mt Meakan (12pm – 5pm)

Return to hotel, dinner (6pm – 8pm)

Kamuy Ilumina (8pm)

Day 3

Drive to Teshikaga (9am – 10am)

Lake Mashu (10am – 12pm)

Lake Kusharro (12pm – 2pm)

Mt Io (2pm – 4pm)

Ozora (Shibazakura Park) (4pm – 6pm)

Drive back (Reach approx. 7pm – 7.30pm)

Day 4

Drive Shiretoko National Park (9am – 12pm)

(Still researching here)

Day 5

Kushiro

Drive to Kushiro City (10am – 11am)

Check in hotel

Lunch at Washo Market (11 – 12pm)

Kushiro-Shitsugen National Park (12pm – 4pm)

Return car

Fly to Tokyo next day