For an anime that labels itself as "Trinity Seven", I never actually believed the substance or quality of the anime itself was ever that of a seven or higher and saw it as a fine anime with cute girls though lacked something very important to be considered a good show. I decided to approach this OVA with mixed opinions and then put the thought "will this anime impress me"? Well, I can admit at this moment that I strongly believe that this OVA alone surpassed the anime itself in every aspect except the story since this episode was just a way to show off the bodies of the Trinity Seven women with a small continuation of the current story right at the end which makes me believe a second season is at least in the consideration process so fans at least can be delighted to know a chance of a new season does exist.
The sole reason I enjoyed this OVA heaps more than the actual show is because it just felt "right". As odd as that may sound, please hear me out~! The show was fine and not anything bad and is better than various other harems, but it felt lackluster in both comedy and this was a case I wanted less story and more ecchi and comedy routines, just as this OVA did really well. The comedy hit home and the characters interested me more for that very reasons. Though, if you aren't a fan of ecchi/harems and feel anime boobies ruin anime then skip the series and this. We all have our opinions and you deserve yours!
If you're a Trinity Seven fan: Watch this.
If you're an ecchi fan: Watch 1st season and then this.
If you hate harems: Skip Trinity Seven