Do you think the reason that Starjun mimics Midora's hair is similar to children imitating their dad ?
Welp. I ended up going WAY more into this than I thought while looking for image references for this so I'll give ya the TLDR of my original headcanon and if you (or anyone reading this) wants to crawl down the rabbit hole with me, feel free!
TLDR; I (originally) thought Starjun's hair was similar to Midora's out of respect/admiration/possible sucking-up. (Because Midora's self-centered, Starjun could've been copying to win brownie points like how Setsuno makes Toriko wear his hair like Jirou, or Starjun did it unconsciously because he wanted to be more like Midora). And you could attribute that to a father-son sort of thing (y'know, 'child see, child do'). If that's what you mean?
If you think it's more of a familial thing, I would say there's definitely some foreshadowing hidden in the hair symbolism. (Details/spoilers below the cut because while I was responding to this I dug myself down a helluva rabbit hole).
ALRIGHT BUCKLE UP BECAUSE MOD CHEF HAS REALISED SOMETHING TRULY AWFUL ONCE AGAIN
I'm gonna start by pointing out that in the Toriko universe, although genetics is kinda played with loosely, it's established that people will copy the hairstyles of their relatives more than their mentors/role models.
The easy thing to do would be to say "look at how none of the Kings have even remotely similar hair to Ichiryu", but we also have no reference for the Kings' predecessors (other than Toriko, but we'll unpack that later).
Instead, let's take a look at one of the only actual genetic relationships shown on screen: Jirou and Teppei.
We already know that Jirou and Teppei are biologically related, but more than that, we know that Jirou and Teppei went down completely different paths. Sure, Teppei clearly respects Jirou, but it's because Jirou took him Gourmet Hunting that Teppei decided not to become a Gourmet Hunter.
They went two completely different routes, Teppei not mimicking Jirou, and yet how do they style their hair?
The exact same way.
This is what I realised that sent me down the rabbit hole.
(Before anyone mentions it: Yes I know Acacia and Ichiryuu had similar hair but that was only temporary because Acacia had gotten a power-up. For the most part Acacia's hair was in that very, very long ponytail.)
We all know Toriko's family tree is a wreath. Let's take a look at Acacia's weird family, namely I want to look at Midora and Starjun, since that's what you're asking about.
Obviously pretty similar: They both have long, choppy black hair that sorta hangs in tendrils.
But you may notice something kinda interesting: Midora's hair has a much messier cut and some of it hangs into his face. It's not like the other disciples, but it's definitely familiar...
Hm... where have we seen a character with messy black hair that hangs into their face?
We know that Midora isn't Froese's biological son, but obviously there's some sort of parallel to be drawn here. And once you make that connection, it's easier to then realise how Starjun is part of this backwards family. Especially once you consider how Starjun's rank in Gourmet Corp is officially a 'Sous Chef'. And Froese was a chef.
And not just any chef! She could perform God Cooking. Let's take a look at what her God Cooking looks like...
Hmm... where else have we seen that?
HMM...
Maybe I'm cherry-picking for what I want to see, but doesn't Starjun's hair look a lot more like Froese's? Froese's hair is everywhere but it's got a flow, the ends are wavy, but smooth. Clumps flow in similar directions, and are generally pretty thick. Notice how Midora's hair has much finer clumps going in other directions? Even Starjun's face is shaded like Froese's. Perhaps there's an argument to be made that Midora's similarities to Froese are something of a red herring, with the real foreshadowing coming from Starjun? Maybe that Midora's design is almost a mockery of Froese's -- similar, but almost more tentacle-like, more visually threatening? Or perhaps that Midora's similarities are an attempt to copy her, but not getting it quite right?
Admittedly, it's more likely that Shimabu decided that "Evil Villains with Bug-Like or Tentacle-Like Motifs = Long Black Tentacle-Like Hair" was an easy design, but I would say it's not a stretch to assume he made Starjun's hair similar to Midora's in order to solidify that Starjun is the Important one with some sort of connection to Midora (especially since Starjun is the only non-bug-themed Sous Chef).
You can't ignore Occam's Razor. And the simplest explanation is that Shimabu drew inspiration from Dragon Ball and decided that more power = more hair. But where's the fun in that?