Could be an unhappy Pieris japonica with chlorotic/ yellow leaves.
Do you have alkaline soil or stagnat water in the soil?

Hi, it rains alot where i live, so maybe the soil is too wet for its liking, is there anyway i can test the drainage of the soil? i m thinking i could just dig a hole pour water into it and see what happens?
Also how would I know what kind of soil i have (I am very new to gardening)

if you gave us .. a broader view of the garden ... we might see other plants.. that allow us to intuit the situation better ...

are you new to the garden ????

many hardcore gardeners ... buy yellow versions of plants.. on purpose... that is the way they are supposed to be ... but my thought is... you could probably understand that..if you have a nice garden collection ...

but.. if it looks like... the prior gardeners.. just slapped a few things in.. here and there... then there is a good chance.. they did not know.. the soil requirements of some garden splurge.. they just liked it.. at point of sale ... and now its suffering ...

in other words... if you try to make a plant that is yellow.. not yellow... you may harm it ...

but if its supposed to be green... then there are simple remedies ...

in the mean time.. could you talk to a good nursery.. and ask how you get a soil test done ... i am very limited on what your options are in france ... here in the states... every county in the US will offer soil tests for a modest fee ...

ken

Not sure if this would be available in your area but
maybe the experts would weigh in on:

{{gwi:2119507}}

Here is a link that might be useful: Illicium parviflorum 'Florida Sunshine'

I agree with Linaria. It looks to me like an unhappy Pieris. The flower buds are visible.