Ki-61/100 Hien Performance

[Shortround6]

How could such a slender, delicate wing be so rugged? The weights of the Ki-61/100 in comparison with similar fighters do not indicate heavier structure.
How were three spars possible without being heavier?
I thought the Me 109 had a main spar with two auxiliary spars as well.

3 small spars might be both stronger and lighter than 2 big spars. Remember that the skin handles some of the load/spreads it out.
It is going to cost more to make however.

auxiliary spars are sometimes just places to hang the flaps and/or ailerons. they sometimes to not transfer torsional loads into the fuselage or the opposite wing structure.

Please note the Ki-61/Ki-100 did not have large gun bays interrupting things in middle of the wing.

 

[spicmart]

The details about the Ki-61-I/Ki-61-II/Ki-100 structure:

The forward wing spar must have been almost identical with the wing leading edge.

@ Shortround6 It looks like the Ki-61 also had more of 1 main wing spar and 2 (or just 1?) auxiliary spars on this illustration rather than what one would call 3 spars.
And the Ki-61/100 did have midwing cannons (you meant that?).