That went better than expected.
Also, according to my theory of writing at least serviceable adult/minor age gap relationships, one of the prongs (establishing that the younger party is of equal or greater maturity) was established in this chapter. At least, the older party is claiming so.
...and Natsumi doesn't have any power over Yuuto, let alone power that she leverages over him-- so that's the other prong satisfied.
Is- is the onee/shota(?) a go?