Choo Sunghoon and Sarang are going to Osaka to meet Sunghoon's parents. Tablo is recovering from shoulder surgery, will he be able to look after his daughter Haru? Lee Hwi-jae has become the god of child care, now that he's familiar with taking care of his twins, Seoeon and Seojun. He goes to see an eye doctor to check the twin's eyes. The charismatic actor Jang Hyunsung is actually a very clumsy person at home. He's very friendly with his two sons, Junu and Junseo. He teaches Junseo how to ride a bicycle without training wheels.

Sunghoon and Sarang have so much fun in Osaka, Sarang spends her birthday at her grandparents house and experiences various things she had never done before. Meanwhile, Tablo and Haru goes to the aquarium to see fishes which is Haru favorite thing in the world. Hwijae, worried about the twin's eyes, takes them to an eye doctor. They get their eyes checked up and Hwijae gets so scared by the sound of their crying. Also he takes them to a baseball park with him. Hyunsung goes to Junu's parent-teacher conference and gets surprised by Junu's letter and his performance in school.

Sunghoon and his dad wants to teach Sarang judo. Sarang is now getting along well with her grandparents and Sarang's mom, Shiho Yano arrives in Osaka. Haru wants to treat her dad's arm. Tablo starves for two days and realizes how hard it was for his wife Hyejung to look after Haru. It's Haru's first time spending two days without her mom. Hwijae's wife told Hwijae to go to culture center. Will he be able to take care of the twins? Hyunsung tries to cook curry but he doesn't even know how to peel carrots, also Hyunsung and his boys prepare a surprise for their mom for their wedding anniversary.

Sarang's suffering from constipation. To show off his cool side, Sunghoon takes Sarang to his photo shoot. Also he takes her to the gym. Sarang usually cries but she stays quiet and Sunghoon gets surprised by that. Tablo and his family has breakfast, after Hyejeong leaves, Haru dances to K-Pop. Tablo plays many of his songs to Haru to get her opinion. Hwijae's twins are growing really fast. They can now stand up. After the boys advancement test in taekwondo, Hyunsung goes to the market where he gets lots of attention, to cook something tasty for the boys.

Haru learns to spend more time with Tablo band mate and friend, Tukutz's baby. Junu and Junseo go shopping for clothes with Hyunsung. Hwijae takes the twins to a wedding and they continually suffer from stomach problems. Sunghoon takes Sarang to Hakone hot springs, but it's not the trip he had expected since Sarang refuses to go into the hot spring and won't let him either. Guest stars: DJ Tukutz with his son Kim Yunu, Lee Young-Hyun, Jeong Hyeong-don via phone call, Jeong Jun-ha via phone call

Haru goes to a fishing park with Tablo, they catch their first fish ever. Sarang continues to have constipation problems. Sunghoon and Sarang are still at Hakone, they have a craft day where they make an souvenir for mom Shiho. The twins have diarrhea problems and special nannies Choi Hongman and Lee Hyundo come to help. Hwijae takes Seoeon and Seojun to a baby play facility where Seoeon encounters his first love. Junu and Junseo learn about pocket money and finances. Guest stars: Lee Hyun-do, Choi Hong-man

Sarang's mother, Shiho Yano gives a ton of chores to Sunghoon, he has to take Sarang to get her hair cut, make juice for her constipation and so on. to avoid Sarang from getting mad at him he takes her to the Disney store and lets her pick out whatever she wants. Haru visits the zoo with Tablo, unlike her friends she isn't scared to touch the animals at all. Hwijae tries to feed his twins baby food but the twins start fighting, later he takes the twins to the TV studio. Junu and Junseo start the day by fighting and Hyunsung takes them out to fly a kite. Hyunsung also brings his sons to his mother's house to make kimchi. The four dads gather together to tape an episode of KBS Happy Together Guest stars: Yu Jae-suk, Park Myung-su

The four dads continue with their taping of Happy Together. Shiho gives Sunghoon a list of things he needs to do and one of them is to buy a Christmas tree. It's his first time decorating a tree. Kwanghee of ZE:A visits the Choovely family. Tablo wants to make this Christmas special so he disguises himself as Santa Claus but Haru's reaction isn't something Tablo expected. The twins get to celebrate their first Christmas. Hwijae takes them to a toy store but they keep giving him a hard time. Hyunsung makes egg bread for the first time for Junu and Junseo. Guest stars: Yu Jae-suk, Park Myung-su, Shin Bong-sun, Park Mi-sun, Hwang Kwanghee, Jeong Eun-pyo and his family Guest stars: Yu Jae-suk, Park Myung-su, Shin Bong-sun, Park Mi-sun, Hwang Kwanghee, Jeong Eun-pyo and his family

Sunghoon and Sarang visit Mt. Fuji, but Sarang isn't interested at all. Later Sunghoon prepares a surprise party for Shiho. Tablo and Haru visit Haru's grandpa's grave. She writes a card to him. On the morning of Hyejung's return, Haru surprises her dad with the song she wrote. The twins are growing really fast, they even try walking with the walker. Hwijae takes them to a swimming pool for babies to swim. Hyunsung tries making bean sprout rice but Junseo seems to know how he should make it. Junu expresses how he feels, he thinks his mom favors Junseo since he's younger. Guest stars: Jeong Jun-ha via phone call