Make Ahead Bento Ideas?

Hi Maki, I want to make a few bentos ahead of time to put in the fridge (to be consumed within 2-3 days). Do you have any ideas as to what would keep decently? I'm visiting my boyfriend who is a workaholic and eats terribly (or not at all!), so I'd like to make him a few bentos to take to work after I leave. He's Japanese and has very Japanese tastes as far as bentos go :) I'm visiting him here in Tokyo so it's easy to find everything. He especially loves shiitake and tsukemono but will basically eat anything. I made the shiitake takikomi gohan and kabocha from your book today for his bento and he said 'yatta' lol. Your book is the best gift he ever bought me for himself! I've made some tsukemono (from your book and off the net) and other things like kinpira and left them ahead of time, but would like to assemble as much as I can to make sure it gets eaten right ( assembly on his part required!), so it's not just rice and tsukemono thrown together for lunch, like happened last time! Also, this is a side question - I was looking at the five ingredient rice with chicken (it's p.40 of Just Bento) and was wondering, do you cook the chicken first before putting it all together in a rice cooker? And if that safe to put in the rice cooker with a timer the night before? Thanks, I love you and your book so much! Ever since getting your book bentos are kind of becoming my hobby! I make them for everyone! <3 Jennifer