1. Suddenly 4 People in the Family?!

Miyu Kōzuki's parents had moved to the United States to work for NASA. Miyu has been told she is to live with her parents' old friend. She arrives, and it turns out to be a Buddhist temple. She meets her parents' friend, the temple monk, Hoshou Saionji, and his teenaged son, Kanata. The monk soon leaves for India for religious training, leaving Miyu behind with Kanata. Shortly after, a UFO flies into the house, and inside were an alien baby called Ruu and a "sitter-pet" called Wanya. They all then decide to live in the temple together. Kanata peeps at Miyu while she's showering, just as Miyu has seen him changing.

2. Ruu-kun is Climbing the Chimney

It was Miyu's first day at her new school. She finds out that Kanata has a fan club, and he is the class president. Miyu meets Christine Hanakomachi, a half-French girl who fancies Kanata. During class, Miyu spots Ruu flying outside. Kanata and Miyu chase after Ruu. Ruu ends up climbing a chimney, forcing Kanata and Miyu to climb it too.

3. Chris Drops By

Chris and her friends came by Kanata's house to have a welcome party for Miyu. But their home turned out to be a disaster. They needed to take down floating items and hide Ruu and Wanya from their guests. Chris misunderstands Miyu and Kanata's relationship, after they discover Ruu.

4. Momoka and the Necklace

Kanata and Miyu both go out with their friends. Before Miyu leaves, she notices that her necklace is missing. A crow has taken it. But 3 year-old Momoka chases the crow away and retrieves the necklace. While shopping for dinner, Wanya loses Ruu. Ruu finds Momoka with the necklace. They both are together, when finally Kanata and Miyu find Momoka and Ruu. Momoka starts referring to Ruu as her boyfriend.

5. Miyu's Awful Cuisine

6. Mama Comes Over on Mother's Day

7. Ruu-kun, Popular at School

8. Ruu-kun's Acting Debut

9. A Date in the Park Between Cousins

10. Playing with Spaced-Out Santa

11. June, on Father's Day ... Papa Comes

12. The Mysterious Boy, Yaboshi Seiya

13. The Mysterious Planet Sharaku

14. Help! Transforming Wanya

15. Mikan Ran Away, Saionji!

16. Ocean and the Lovers' Tree

17. India's treasure is SAIONJI?

18. Momoka's Passport

19. The Mysterious Home is Miyu's Real House?

20. The Off-season Home Visit

21. Principal, Monkichi Reunite

22. The Hike of Fear

23. Everyone, Gather at Saionji's

24. The Blackout Halloween

26. Yaboshi Saiya's Warning

27. A Correspondence with Ruu's Parents

28. Sister Comes to Saionji

29. Nanami and the Mysterious Tsukemonoishi

30. Wanya Wanya

31. The First Christmas with Saionji

32. Chris, Ski, Mansion

33. Kanata's Childhood Friend

34. Kanata's Promised Date

35. Bye Bye Wanya

36. The Heiomachi Onsen Excursion

37. Miyu's Idol Debut

38. Ruu-kun Has Multiplied

39. All 100 Ruu-kuns, Gather!

40. Kanata's Rival Appears?

41. Kanata and Nozomu's Showdown

42. Where is Okame-chan?

43. The Family Assembles at Saionji

44. Koinobori Aren't Scary!

45. Cinderella Inside the Book

46. Chris and the White Whale

47. Miyu and Mini-Miyu Go to School

48. Santa and Kanata's Weird Pot

49. Mizuno-sensei's Mysterious Trip

50. Stop it, Lazy Wanya

51. Mika-san's Mysterious Promise

52. Saionji's Ghost stories and the Mysterious Koishi Stones

53. Miyu and Kanata Go to America

54. Everyone but Santa goes to America

55. The Weird Object That Seiya Left Behind

56. Mecha Wanya Attacks!

57. Nozomu and His World of Dream

58. Our Pet is Number One

59. Peppo, Ruu, and Wanya

60. Mikan's Work Place is the Saionji

61. Miyu and Kanata's First Kiss

62. Nagging at the Saionji Temple

63. Spooky Mountain Villa

64. Meeting a Penpal

65. Inventions are so Boring

66. A Friend, a Rival, a Competitor

67. Teru Arrives From Planet

68. Bowmeow Versus Mister

69. Ousted Guava Falls in Love

70. Momoka’s Christmas

71. The Seven Gods of Fortune

72. The Same Kimono as Miyu

73. Miyu and Little Boy Kanata

74. Goodbye Evil Gang

75. Valentine’s Day in Heiomachi

76. Ruu in the Lead Role at the Cultural Festival

77. On the Night of the Full Moon

78. See You Again