Seven day Tokyo itinerary

I'm off to Tokyo again for the 2nd time in March and trying to organise stuff to do. I've already been to Harajuku, Akihabara, Asakusa and Disneyland and looking for other things to do. I was originally going back to Disney but read that March is a busy month so tbh I see no point going back now if its like that. I was also going to Fuji Q but heard lines are like three hours long sometimes so too long for me. So far I'm thinking of heading to a tattoo friendly onsen for the day in Hakone imperial palace and maybe a day trip to Nikko or Kamakura or maybe a another city/town/village near Tokyo. Any advice on other places that could be interesting. Or interesting tours. I'm in Tokyo from 6th-14th or March than off to Osaka which is pretty much planned.

If you like flowers, I would highly recommend a trip to Kairakuen in Mito. Kairakuen is one of the 3 big gardens and is usually given short shift because out of season it's not as impressive as Korakuen and Kenrakuen. However, from February to March is the time to visit when the ume is in bloom and it's really quite pretty.

Kamakura is really nice.

If you're interesting in skiing or snow activities there is always Gala Yuzawa or Shiga Kogen.

It really depends on what your interests are.

Kamakura with Enoshima as a stretch goal makes a wonderful day trip.

Mt Takao is a total change of scene, nearby but feels totally different.

I also like Kawagoe for a day in an 'old town' that is very accessible to Tokyo.

Have a wonderful time in Japan!

There are loads of good places to go to. I was going to mention Kairakuen for the ume, but it's already out there for you.
You could also consider Nikko, Hakone, the Fuji 5 Lakes area, Karuizawa, Kusatsu, Izu, Kamakura & Enoshima, Kawagoe, Takao, Okutama, Yokohama, Nokogiriyama, Minakami, Showa Kinen Park, and more. There are regional rail passes you can get for nearly all of them. If you go to a few, the Tokyo Wide Pass might be a godsend.