"エコ魔法少女" (Eco魔法少女) seems to be a Japanese title, possibly for a magical girl anime or manga series. However, I couldn't find any information about an official series with this exact title.

There are a few possibilities:

1. This might be a fan-made or unofficial series that doesn't have official distribution.

2. It could be a misspelling or variation of another title.

3. It might be a work in progress or not widely released.

If you're looking for magical girl series in general, some popular ones include:

- Pretty Cure (Precure)

- Sailor Moon

- Magical Girl Lyrical Nanoha

- Cardcaptor Sakura

Without more context about where you heard about this series or what it's about, it's difficult to provide more specific information. If you have any additional details, I'd be happy to try and help further.