The cuckoos continue their shenanigans.
Nagi goes on a secret date with Hira, and gets caught red-handed by Erika. So she gets jealous and forces Nagi to go on a date with her, too! During that date, it's revealed that Erika might actually like Nagi, you know, as in "like like". Things continue to be awkward between Nagi and Sachi, who has secretly been in love with her brother, and now that everyone in the group knows they aren't actually related, her feelings have bloomed. Nagi, unaware of this, stumbles upon his adopted Father's love letters, and gets caught red-handed reading them, by none other than the aforementioned Father. He tells Nagi to close his eyes, relax, and think with his heart as to who it is he loves. Nagi does so... and Hira, Erika, AND Sachi all appear in his thoughts! This troubles Nagi so much that he bombs the next test, and loses the coveted first place spot the he and Hira have been battling for. As for Hira, it's now revealed that she, too, has feelings for Nagi. She somehow realizes that Erika can cheer up Nagi, and make him smile, which Hira thought only she could do, and this greatly saddens her. Next, the local street festival! Nagi and Sachi have to help the family food stand, and while setting up, none other than Hira appears, and seems genuinely happy to see Nagi. They make plans to tour the festival later. However, later on, Nagi ends up with Erika on a high platform just as the fireworks start. It looks like Erika might confess to Nagi, or even kiss him, when suddenly, Hira appears, and while Nagi tries to convince Hira things aren't as they seem, Hira bursts out that she's been told separately that Sachi is Nagi's little sister AND also Erika's little sister (which technically is true, Sachi IS the little sister of both Nagi and Erika, just in different ways), and looking sorrowful, Hira demands to know the truth about the nature of Nagi's and Erika's relationship! So this ends the chapter, on a cliffhanger. I have a feeling that there's going to be some serious heartache next volume, from several directions. Just when it seemed Hira was really starting to like Nagi, she starts getting inadvertently hurt, and Erika is the root cause. Nagi is going to have to do some serious soul-searching, and decide who it is that he truly love... Hira, Erika, or... maybe Sachi?