Yeah, Daiba isn't all that interesting at night, the view is nice, but that last for like 5 minutes.

Thanks Sangetsu. Sound like it is better to go Odaiba in the morning then proceed to DisneySea. Will it be too rush to visit DisneySea after the Odaiba as I believe my two kids are very keen to enjoy the attractions in DisneySea. By the way, I will be staying in my relative house near Chiba, understand is near to Tsudanuma station, so how should I proceed from Tsudanuma station to Odaiba then DisneySea ? Thanks !

You should be able to take the Sobu line train to Nishi Funabashi station. From there you can get the Musashino line train to Maihama (Disney), or Shin Kiba (where you could change to the Yurakocho line for Toyosu, and then the Yurikamome line for Odaiba).

Your kids will enjoy Odaiba too. Palette Town has a few rides, as well as the big Ferris wheel, and there are often performers doing things like juggling acts, animal tricks, or other things. Muscle Park is located in the Decks building, if I remember right, and there are some interesting things for kids to do there as well. And then there's the beach, which you won't want to miss. You can get pictures of the Rainbow Bridge and the Tokyo metro skyline from there.

The Sobu line also runs all the way to Tokyo station, you can transfer to pretty much any line there, though the Keiyo line platform is a long walk across the station. The Sobu line platform is on the Marunouchi side of the station, so you can simply walk out of the station at the Marunouchi exit and walk to the Imperial Palace. The walk is less than ten minutes.