高取英原作的超话题作。圣未加江罗学院表面上是一所校规严厉的女子学校，但其中隐藏着惊人的阴谋......
个性活泼开朗有时候显得有些大大咧咧的水无月遥（田村由加莉 配音）、成熟稳重颇具大小姐风范的神无月葵（能登麻美子 配音）、从意大利转学而来的天才少女叶月胡桃（钉宫理惠 配音），活泼可爱的三人平日里在学校中是无话不谈的好友，过着平凡的校园生活，但每当夜晚来临，她们便会变身成为拥有超能力的魔法少女。 三人的目标，是寻找价值连城的天使像，邪恶而又贪婪的地下拍卖组织Black auction得到了它，企图通过它来牟取暴利。成绩优异的学生会长如月唯人（桧山修之 配音）、随叫随到的万能管家长月平之丞（清川元梦 配音），是他们在背后默默的支持着少女们。
300年前，沿海居民不堪忍受外来殖民侵略者的压迫与搜刮，组成海盗与殖民者作战。海盗们将殖民者的财宝抢来埋藏在一片神秘海域，传说堆积如山的财宝光芒闪耀，变成美丽的彩虹，从此海盗和他们的宝藏以彩虹而闻名。自称彩虹海盗后人的海狸波波（谢元真 配音）将传说编成故事说给海底居民们听，结果引来了寻找财宝不成的海马家族以及凶狠神秘的独眼鲨（谭满堂 配音）。危急时刻，波波得到小潜艇阿力（范楚绒 配音）的救助。他们带上小潜艇贝贝（洪海天 配音）以及海马家族，踏上了寻找彩虹宝藏的旅途。 浩瀚无垠的大海尽头，等待这群冒险者的将会是什么？
In this season, the show went back to airing one new episode a week, but stayed in the hour-length format, filling up the second half-hour with episodes from previous seasons and some of the prime-time specials from the 1980s. This entire season, along with the second half of season 6, is available on Garfield and Friends: Volume 5 DVD set. Also worth noting is that here, a new theme song was added that was written by J.R. Johnston and Neil Panton. The theme was sung by J.R. Johnston. This theme song was not shown internationally, and as a result, it does not appear on the DVDs (although Garfield's quotations are kept intact). This new introduction sequence used most clips from Seasons 5-7 and a few from the first two seasons, as well as Garfield in Paradise and Garfield's Feline Fantasies. The episodes stopped using a few seconds of the theme playing in the episode title cards after season seven's fourth episode; music from the episodes were used in the title cards until the show ended, even though season six used music from some of their episodes.
