6D5N is not bad to go Toyko or surrounding area..
1. To see Mt Fuji, I recommend to stay at one of the Ryokan (japanese style hotel) at Hakone for one night.. You will get a good view for Mt Fuji and get also get a calbe car to down to get a ride on the Prirate boat..It will be a nice and relaxing time..
2. For Disneyland or Disney Sea.
its purely upon yur preferrance. Disneyland is full of attraction, most roller-coaster are there..Or getting on a boat in the Little World.. And don t miss the famous Desney Parade!
Desney sae is branded as a romantic,fairy-tale place, especially at night time! And a few desney-related boutique stores..
So if you want a romantic, dreamy feling than screaming on the roller-coaster,the Desney Sea is better..
I personally liked desney land more!
For tokyo city,i will suggest
1. Odaibba-Popular dating spot, have a good view for Rainbow bridge at night, facing the Tokyo Bay. Dining and shopping.. Ferris Wheel is also there..
2. Shinjuku City Hall building (shinjuku western exit from JR or Subway) for great city views on 50th floor for free! better than Tokyo Tower..Having a cup of coffee when you on the top floor.
3. Sensouji (Known as Asakusa Temple)..
4. Tsukiji fish market- Wholesale place for sushi restaurants. Need to go ealr like 9 in the morning to get a fresh taste of Maguro..
5. Yokohama- Got Chinatown for dining, Yamashita Kouen (park) for walking.. lso have a Ferris Wheel at Minato-mirai just a few stops away, can get a beautiful harbour view at night..
6. Shibuya and Shinjuku- for shopping.. Got Issetan, Takashimaya, OIOI etc Department Store at Shijuku.. Got Sebu department store, 109 (a low-priced woman wear shop) at SHibuya..
Zara, Gap, Unikuro (a japanese branded casual wear store)etc..
Oh, don t forget to check out Matsumoto Kiyoshi for cosmetic. They are near to most majoy train station..(I believe Shijuku, shibuya,ikebukuro Station all got one) They carry Japanese Brand like Shisedo,Kenebo, Kao for a reasonable price.. you can also find lots skin care, hair care products.. Where local will go!
7. For eaating- hmm, i can t put it together as Tokyo has way too many restaurants with all types of food you can ever think!
If you like Ramen, instead of going to Ramen museum in Yokohama, you can try aonther 8 stored Ramen street near Shinakawa train station (on the JR line).. Get outof the exit which Prince Hotel is and walk out left side for abt 200 meters, you will find a place full of Ramen- shop.. They all well-known places that represent diff taste in diff region of Japan..
Oh, also try Mos Burger there, they are much better than Singapore ones..
8. Harajuku- Also a shopping, dinng area..
Have a walk down the Gaien-mae Ave, you will reach Omodesando (very fashionable street in Tokyo). Its a nice walk with all the big brands on both side. Its nice to see even don t buy anything..
9, Roppongi Hils and Roppongi Mid twon-A trendly shopping and dining place, specially mid-town is just opened last year..
10, Believe it or not- you are able to go Hiroshima as a Day trip if you don t want to do too many shopping by Shikansen (bullet train).. It will truly be a unforgetable and very powerful moment for everyone to go to the Plaza in the center of the city where you can see the historic marks of Nuclear Bomb.. It will truly set ppl to rethink abt the life..
I can keep going and going, hope it help a little bit.. Now, it makes me missing Tokyo..