HP - The total HP of your party before Leader Skills are accounted for.
Cost - Total cost of your party. Exceeding your max cost will render you unable to use the party.
Leader Skill - The Leader Skill of the assigned leader of the team being displayed.
Below that are options that lead you to:
編成 (Party) - Here you can change the units in your parties.
売却 (Sell) - Here you can sell units.
図鑑 (Catalog) - This displays all the Units you have seen. A box with a ? means you have not seen it. A greyed image means you have have encountered the unit but have never had it yourself. A clear image of the unit means you have it or have had it before. If you tap on a unit in the Catalog you will be able to see its initial stats.