During gym class the boys are outside practicing kicking a soccer ball into the goal, but keep "accidentally" overshooting the ball and going to retrieve it to get a glimpse of the girls in swimming class. The guys are tabulating the approximate breast sizes of their female classmates. Unfortunately when it's Tsubaki's turn, he completely misses the ball and also misses his chance to see Urabe in a swimsuit.
The weather is heating up now that it's summer break. On their way home, Tsubaki notices that Urabe smells nice. Unfortunately it starts raining and neither of them brought an umbrella. As they stand under a tree waiting for the rain to die down, Tsuabki smells Urabe again and asks whether she is wearing perfume. Urabe says she doesn't use that stuff. Urabe smells her arm and says it must be hear sweat, which tastes salty like seawater. Urabe says she likes swimming and the ocean so she visits the beach each year. Urabe offers her arm to Tsubaki to lick. When he does so, he has a vision of Urabe on the beach in a bikini. It seems Urabe's sweat can transfer images just like her drool, unless it's just Tsubaki's wild imagination. When the rain stops, Tsubaki asks Urabe to go to the beach, she agrees.
During summer break Tsubaki and Urabe's drool ritual continues each day. But every time Tsubaki tries to ask Urabe out on a date, or set a time to go to the beach, Urabe hurries off on her bike and is gone before he says anything. Tsubaki decides he needs to be more assertive, so the next day Tsubaki grabs Urabe's bike before she can start pedaling and asks to set a date to visit the beach. Urabe apologizes, saying she will be visiting her father's family for the next few days, but should be free the week after. Tsubaki is ecstatic, when he gets home he has a foolish grin on his face. That night, Tsubaki dreams of having fun with Urabe on the beach.
Tsubaki wakes up early next week to meet Urabe at the train station. Tsubaki makes it just on time, and Urabe says she just arrived too. Also interestingly Urabe is wearing a dark tan. Urabe explains that her father's family lives by the ocean, so when she went swimming she got this tan. When they get to the beach, Tsubaki notices a lot of girls wearing revealing swimsuits. Urabe changes into her black bikini along with a patterned skirt. Urabe says they should eat something first since swimming requires energy. They have yakisoba together, but Urabe pays before Tsubaki gets a chance to. Urabe swims really fast and almost leaves Tsubaki behind. She explains that she has been swimming since she was little, and apologizes, saying she will slow down for him.
While swimming Tsubaki swims underwater to get a closer look at Urabe's skirt, which has an interesting pattern on it. Urabe explains that she usually doesn't wear a skirt, but when she swam at the beach near her father's place the other day, the beach was unoccupied. So she tucked her scissors into her bikini when swimming for her own safety, which resulted in tan-lines. Tsubaki gets a nosebleed and tries to cover it up by offering to race back to the shore. On the train home, Urabe tasts Tsubaki's drool and her nose starts bleeding. Tsubaki explains and Urabe asks if he wants to see her tan-lines again. When Tsubaki says yes, Urabe seems happy and says if they go to the beach again next summer, she will show them to him.