CLAMP School is not just a school - it's a self-contained city. Housing 10,000 students from Kindergarten to Graduate level, it facilitates education for anyone talented, regardless of wealth. At the elementary level, three students lead the student council: Nokoru, the youngest son of the company that built the school; Suoh Takamura, the cool-headed secretary; and Akira, both a talented cook and the council's treasurer. Well-liked and resourceful, the trio is able to help the fairest of damsels with ease. And thus, after saving a sad old woman, Nokoru decides to create the CLAMP School Detective Agency; their goal, to help out any maiden in distress!
In a sad twist of events, five unrelated boys are adopted into a family are then scattered due to the death of their parents. One of these boys, Hanayagi Sakura, struggles to reopen their mother's beloved flower shop and bring the family back together, even though they have no blood ties. The boys each bring their individual talents to the table to help make a unique flower shop cafe, and call it "a flower shop that brings happiness to everyone." With each day a new challenge, the five ‘brothers' greet each customer and provide the care and service they need to fill the emptiness in their hearts.
Both of these shoujo manga are about a gaggle of ridiculously handsome/cute guys that just want to help people and make them happy. Both are fluffy and light-hearted, and if you liked one, I can't see why you wouldn't also like the other.
CLAMP School Detectives is rather lighter than Utena (though this version of the Utena story isn't as heavy as most of the others), but if you enjoyed the over-the-top decadence of the giant, exclusive schools that either of these manga are set in, or the bishounen-heavy student council (Utena's cast also includes some very princely ladies, as well), and mystery elements of one, you'll probably enjoy the other.