Next Adventure, Help?

After coming home from Tanzania, I went straight back to university for my last couple of months of stress! The end of second year was hectic and whilst doing the last few assignments I was also trying to find a place for my boyfriend and I to move into in a matter of weeks, even more stress! But once everything was sorted I could finally breathe a sigh of relief and say I've got four whole months off University. I can hear you all saying this would be the perfect opportunity to go travelling, not this time. 

Having decided to move in with my boyfriend, everything this summer is revolving around our new home and getting it all furnished and just so, which is amazing and I wouldn't of changed a thing, it was the right step for us to do and it's just a different kind of adventure. But that doesn't stop me from seeing some of my friends that our currently travelling the world, i'll always have the travel bug and I look endlessly at different destinations on Pinterest. (Who doesn't) Whilst hoping to learn to drive this year too I also want to have a little get a way somewhere in the UK but that'll be for a blog post around winter, my favourite time of year. So anyway what I was getting onto, my sister has just moved her entire life including her puppy to New Zealand to live their with her boyfriend, which gives me a great reason to go and visit that beautiful country, but with still being at Uni and not knowing what job I may get at the end of it, I am at the moment only planning to go in Dec/Jan 2017/2018, which feels so far off but it will give us time to save and hopefully work it around our jobs. We are planning to go for a month but on the way we would love to stop off in Japan, this stop off would only be for four or five days. So this is where I am asking for help, People of New Zealand and Japan, or those who have travelled there what would you recommend doing? I open to all suggestions, I already have some in my head so I know they are a must if they are suggested.