S1E1 - Muromi-san on the Brink
Takuro Mukojima is outside fishing when he reels up a girl who introduces herself as Muromi-san, a mermaid.
April 6, 2013, midnight
S1E2 - Muromi-san and the Legendary Sea Creatures
Muromi-san gives Takuro her cellphone number and is upset when he doesn't send any messages despite her sending him hundreds. Later, Takuro fishes up another mermaid who introduces herself as Levia-san (Leviathan), a giant sea monster from the Old Testament.
April 13, 2013, midnight
S1E3 - Muromi-san and Old Memories
Levia-san, Hii-chan, and Sumida-san try to get Muromi-san to get over her hatred of marine mammals. She hates them because she had a boyfriend in the Mesozoic era who had developed lungs, but decided to stay in the ocean anyway. She thinks whales and dolphins are his descendants. Levia-san tells Muromi-san that that toothed whales returned to sea after having evolved into complete land mammals, which means her ex-boyfriend either evolved into something else or became extinct.
April 20, 2013, midnight
S1E4 - Muromi-san and the Food Chain
Takkun meets another one of Muromi's unique friends, later the trend continues much to the chagrin of Muromi.
April 27, 2013, midnight
S1E5 - Muromi-san and Twin Mountains
Fuji use to admire Muromi and her gorgeous tail, but the current status of Muromi tail only brings anger.
May 4, 2013, midnight
S1E6 - Muromi-san and Ryuuguujou
After catching an unemployed fish, Muromi tells Takkun about the Ryuuguujou and the evil Otohime.
May 11, 2013, midnight
S1E7 - The Boy, Kappa and Muromi-san
While river fishing, Taku can’t escape the salt water Muromi or her legendary friends.
May 18, 2013, midnight
S1E8 - Muromi-san and the Nice(?) Type
Trapped by a gang of deadly sea animals, Muromi has only one chance of survival.
May 25, 2013, midnight
S1E9 - Muromi-san and the Secret Advanced Civilization
Youthful pride of Curiosity, how far will Taku go to learn more about the ancient civilizations that tried to defy the gods?
June 1, 2013, midnight
S1E10 - Muromi-san Worldwide
Ciel gets the chance to meet a unique cast of characters and later Yeti has to call on Takku for help.
June 8, 2013, midnight
S1E11 - Muromi-san and the Heatwave
Otohime has taken up multiple jobs like selling popsicles. She tells Tak-kun why she hates mermaids and her fall from the top. She tried to take what was left of her money and take a crack crack at the stock market, but that all fell through. It seems that her feud with Muromi is the result of a misunderstanding that is not easily cleared up. The two actually have nothing against one another. Takkun tries to help them out, but things don’t go too well on that front. A night of drinking together with Levia-san may have helped, but we may never know...
June 15, 2013, midnight
S1E12 - Muromi-san and Different Forms of Love
Fuji turns to the one person who might help her convince Muromi to regrow her tail fins.
June 22, 2013, midnight
S1E13 - The Years go by Muromi-san
Muromi is preparing a new years joke while Tak-kun is worried about his future. Muromi gives him some advice and in return, Tak-kun presents her with a present. Muromi then goes to enjoy the hot springs and watch the first sun rise of the new year with everyone.
June 29, 2013, midnight