Incidentally, what are we saving for?
Int 5.
Realistically, though, we're wanting a stat, and 7 isn't enough for any of the stats. Stats are quite a bit more potent than skills, all things considered.
With awareness 4 backing them up, our court skills are about as solid as we could want. There's really very little need to invest in them further. Worth noting that after the Air ring boost, our Awareness is now going to be as high as our Int.
With Reflexes 4, we're doing well for combat situations too - especially the sorts of combat we're likely to see. Note that our reflexes will have increased by *2* since the kenjutsu tournament. Cranking the TN to hit us by 10 is a serious boost, even without the sidebar bit about initiative. Void is effectively a combat stat for us as well - there aren't any other circumstances where we're likely to spend more than two points in a single day. Our overall skills are going to be quite respectable for a bushi of our rank... and that's after we jump up to School Rank 2 (which is hitting after this vote one way or the other - we're at 146 insight).
Perception and Investigation... I'll admit those have their uses, but it's not nearly as straightforward as "we need to solve mysteries. Therefore we need Perception and Investigation." Our social abilities (which we are now *quite* strong at) are also excellent mystery-solving support. Investigation is useful for physically searching through an area or otherwise noticing clues, and, as a contested roll, in ferreting out falsehoods. Unfortunately, the person we'd *most* like to be able to ferret out falsehoods from is Doji Mariko, and you can bet that she has at least 7k4 in Awareness+Sincerity (quite possibly more). We're just not going to get Perception+Investigation up to where we'd need it to be to regularly notice her lying. Given that it's not going to be at a dependable level, it's more of a "might notice useful things" thing - occasionally giving us useful info here or there. 17 exp total would get us up to Perception 3, Investigation 3 - about the "occasionally giving us useful stuff" level. 20 exp would be enough to push us from Int 4 to Int 5.
Taking Int from 4 to 5 takes us from the "smart kid" level to the "actively impressive" level. It gives us, on average, a bit more than a raise on every one of those lore checks we make. It takes us from "serious competitor" to "possible champion" in Hachiman's tournament. It'll make people sit up and take notice and start scheming on how to get us working for them. It will, in fact, make us as smart as we thought we were.