Short spoiler: Still no truth, Naoto's hometown prefecture deduced to possible 8, Luna is for whatever reason still trying to pull a Chizuru on her Kazuya (Naoto)
Long spoiler: Opening pages, both Luna and Kawashina are already getting glazed by some randos, but Naoto steps in before they could talk to the girls, so they backed off. Naoto brings them along away from the two pickup artists, and Luna describes how packed the beach was. Naoto mentions it is like as he saw in TV, which prompts Kawashina to ask if it's his first time going to the beach.
Naoto tells her it was, as he is from a landlocked prefecture. He told Luna he haven't been to the beach yet, so she suggested to go there and might as well invite Hiba and Kawashina along. He then asked where Hiba was, but she's resting in a tent after the drive.
As Luna is getting ready to play at the beach, and Naoto is getting ready to make the day "the most fun day ever" for Luna, Kawashina tugs Naoto's shirt and whispers to him that it's her first time at the beach as well, they're both going to have their "first time" (at the beach) at the same time...
And play at the beach they went, Luna tiring herself first so she rests in the same tent Hiba was in, leaving Naoto and Kawashina to go and explore with just the two of them, getting a brief moment. Hiba, who woke up, asks Luna if she's worried. Luna tells her she's not so over-protective to be worried, but Hiba is asking if Luna's worried that "Nao-kun" is going to be taken away because it shows in Luna's face.
Chapter ends as Luna claims nothing of it as Nao-kun isn't hers, despite Hiba thinking Naoto would claim "Big Sis Luna" to be his. Luna laughing it off saying him having "Big Sis Luna" is fine. But with a sad expression on her face says she can't give Nao-kun "Luna".
Landlocked prefectures include Tochigi, Gunma, Saitama, Yamanashi, Nagano, Gifu, Shiga, and Nara.