Janna's at her strongest when buffing another ally. If you can harass her ally, it will weaken her ability to fight you.
Save an interrupt ability for when Janna uses her ultimate.
Listen for the charge up sound on Howling Gale in case Janna is trying to hit you with it from off screen or from brush.
The stats shown on this page highlight some influential Yuumi vs. Janna matchup statistics that can help us understand the distinctions between the two. For instance, Yuumi’s KDA ratio ([kills + assists] / deaths) of NaN is greater than Janna’s ratio of NaN, indicating that Yuumi may be more central to her team's team fighting capability than Janna..
Yuumi usually has a similar longest kill spree as her counter does. Typically, she takes less damage than Janna. This is usually reflective of differing health capacities; however, it can also illustrate that the champ with more HP has less mobility and thus is not able to flee from further harm when engaged or poked.
Both LoL champions are great. Both have their strengths, weaknesses, and counters. In League's current meta, Yuumi usually loses when playing against Janna, with a 44.1% win rate. Therefore, Yuumi makes a bad counter to Janna.
While Yuumi does have a much lower win rate compared to Janna, when on opposite teams, Yuumi also has a much lower level of difficulty that makes her a less difficult champ to develop with. You may get destroyed when picking Yuumi into Janna.
Additionally, Yuumi has a lot of CC and other utility, a similar amount to Janna. This makes her just as valuable during team fights, especially when fighting champions with a lot of burst damage.
While there is not one best champion for every situation in League of Legends, in Yuumi vs Janna matchups, Janna is the better champ with a much lower win rate, less champion complexity, and a similar amount of utility to help out your allies during team fights.
Yuumi is a terribly counter for Janna. You will do well by focussing your strategy on keeping up your CS and destroying objectives. If you do that, you should hold your own as Yuumi against Janna.
If you would like to learn all of the intricacies of Yuumi in order to counter Janna during both the laning and mid / late game phases of League of Legends, you should continue reading to pick up a few extra tricks and insights into this matchup. If you listen to the build and tips presented above, you will increase your win rate by a lot and be that much closer to League of Legends pro players.
Yuumi typically gets less CS compared to Janna. Champions who typically don't take much CS usualy don't have to have much CS to be valuable teammates, such as sup champs. They are capable of scaling properly off of their abilities and first items alone. Yet, champions with a lot of CS, such as hyper-carries, often require several high cost items to be effective. In either case, try to do better than the numbers displayed here to do well.
The most crucial items to use in your Yuumi versus Janna build consist of Ardent Censer, Dream Maker, and Imperial Mandate. When Yuumi included at least these three items in her build, she performed significantly better countering Janna than with many other typical builds. In fact, Yuumi had an average winrate of 44.1% when countering Janna with these items in her kit.
To have the best probability of coming out on top against Janna as Yuumi, you should equip the Summon Aery, Manaflow Band, Transcendence, Scorch, Cut Down, and Presence of Mind runes from the Sorcery and Precision rune sets. Out of all the rune sets players used for Yuumi vs Janna fights, this set of runes yielded the best win rate. Notably, these runes provided a 44.1% win rate overall.
By default, tips, statistics, and builds on how to beat Janna as Yuumi are given for all ranked divisions. If you want to scope the stats and builds to an individual division, you can use the selection menu located earlier on the page.