As a commemoration for the 25th anniversary of the Mana/Seiken Densetsu series, Square is packaging 3 of their well known mana titles such as: Final Fantasy Adventure, Secret of Mana, and Seiken Densetsu 3 (unreleased in US) in one physical cartridge media for the Nintendo Switch and it is coming to Japan on July 1st.

It is unknown if the collection is being localised to the west (will update this thread if it, indeed, gets a localization announcement.)

Source Article:
Seiken Densetsu Collection announced for Switch - Gematsu