Sakura, Ino, Anko, and Naruto were currently riding a small fishing boat they'd rented from the chatty fishmonger, who'd very conveniently been there at the right moment to deliver exposition. Though sailing at night in this region was notoriously treacherous thanks to the strong sea currents surrounding the isles of the Land of the Sea, Sakura wasn't too concerned about drowning, since they could all walk on water.
"There's our destination," said Anko, pointing at the sparse lights flickering in the distance. "We're almost at Mother Island…"
Modernization hadn't yet reached these backwater lands the way it had the Hidden Leaf. There wasn't even a lighthouse to guide passing mariners or fishermen, so no wonder their ships kept sinking!
"What's that song you're humming?" asked Ino, pricking up her ears. "I've never heard anything like it before…"
Bored to tears by the slow pace at which they were travelling, Sakura had started humming 'Fubuki,' the first ending theme from the Kantai Collection anime. Sailing on a boat had stirred up memories of her favourite waifu collection game, in which players collected 'Shipgirls,' to send into battle against kaiju.
'Imagine if we'd received a Kancolle System instead of a Manyuu System,' said Inner Sakura with a laugh. 'The anime adaptation of the game is a close second in my list of favourites!'
If they were going to be fighting against sea monsters, then being able to turn into a 300-metre-tall water-skating Shipgirl weighing thousands of tons and armed with autocannons would certainly be more useful than the pair of uselessly large flotation devices on her chest, which made it impossible for her to dive…
(The lore's actually not too clear on the size of Shipgirls, alternating between human-sized and gigantic, depending on the adaptation.)
"I think it's catchy," said Naruto brightly, energetically paddling the boat. "I—"
The boat suddenly came to a jarring stop, almost as if it had hit a rock. Waves started battering the boat's hull, causing the vessel to rock back and forth…
"Watch what you're doing, Naruto!" said Ino angrily, before adding, "turn around, Sakura, you're distracting him with those things! I do not want to get these new sandals wet, ya hear— iyaaaaa!?"
A long rubber-like arm suddenly shot out from the sea and coiled around Ino's throat, lifting her out of the boat and into the air.
"Ino!" shouted Sakura, unable to react in time, as her back had been turned at the time.
"Hidden Shadow Snake Hands!"
Large brown snakes sprouted from Anko's sleeves, but their fangs fell just short of their target. Realising that her Jutsu wouldn't make it in time, she jumped off the boat to intercept Ino before the long arm constricting her dragged her beneath the waves.
"Take care of the boat!" Anko shouted, before plunging into the icy waters.
That was easier said than done— a whirlpool had just sprung into existence less than twenty metres away, sucking in everything around it in a wide radius…
"It… won't… budge!" grunted Naruto, pulling on his oar as hard as he could. "It's stuck, y'know!"
The boat was beginning to circle around the perimeter of the whirlpool, spiralling closer to the centre with every passing second. If Kakashi had been there, then perhaps he would have known how to counter or cancel out the attack, but unfortunately, Water Style wasn't Sakura's speciality. There wasn't much she could do on that front, but that didn't necessarily mean she had to go down that route…
"Chidori!"
Sakura's right hand erupted in electrical arcs.
If she couldn't beat the Ninjutsu, then she would just have to beat the caster! Sea water conducted electricity very well, so assuming the Ninjutsu's caster had to be nearby to maintain it, then her lightning would surely reach him— though she would have to be very careful to not accidentally hit herself in the process.
While Electric types were super effective against Water types, the reverse was also true. It was like spilling water on electronics— a short-circuit was always just a glass of water away!
"Shannarooo!" Sakura shouted, leaning over the side of the boat to thrust her hand into the water.
However, before she could do so, two hands shot out of the ink-black waters and grabbed her by the wrists. Sakura's vision swam as a feeling of lethargy washed over her, and before she knew it, her Chidori had gone out…
"Let go of Sakura!" yelled Naruto, letting go of his oar to deliver a sharp kick at the closest hand sticking out of the water.
The two arms draining Sakura of her chakra abruptly dissolved into water the instant Naruto made contact with them, and the feeling of being sucked stopped just as abruptly. This enemy was undoubtedly very crafty— they had sent a Water Clone to drain her of her chakra from a distance, Bluetooth-style…
"Nice assist, Naruto!" Sakura called out to him, flashing him a Kakashi-style thumbs up.
Now that she was thinking about it, it was probably a good thing that the enemy had stopped her from doing what she'd been about to do. After all, Ino and Anko were still down there, under the sea surface…
"I'll summon some help!" declared Naruto, tearing a gash into his thumb with his teeth. "To fight a sea monster, you just need another sea monster!"
There's always a bigger fish, as some say!
"Summoning Jutsu!"
As they continued spiralling down the drain, Naruto performed a series of hand seals (demonstrating that he could use ordinary Ninjutsu, but that he just chose not to), before slamming his palm against the boat's keel. There was an explosion of white smoke, and… out came a tiny toad.
"Why is it you!?" said Naruto incredulously. "Where's the Toad Boss?"
"Is that salt water I smell?" said Gamakichi, sniffing at the air. "We freshwater beings can't deal with salt water, I'll have you know! No way dad's coming under these conditions!"
Sakura hadn't learned how to summon Katsuyu yet, but she would have known better than to try and summon her here! After all, slugs and salt don't pair well together… unless you happen to be French.
At this point, there was no saving the boat, so Naruto and Sakura hopped off and landed safely on the water's surface. Together with Gamakichi, they watched glumly as their ride was torn apart by the raging currents— a floating pile of shattered wooden planks spiralling down the whirlpool's maw and splintering into smaller pieces, before getting sucked down to the seafloor…